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Navigating social systems : information behaviour in refugee integration
Get PDFThis thesis reports on an information behaviour investigation into refugee integration, undertaken to understand how refugees navigate complex integration processes and systems. The aim was to find person-centred information needs, relationships and sources that could inform the design of person-centred integration systems. The study was carried out through an interdisciplinary synthesis of academic literatures and professional practice. Theories of information behaviour were synthesised with principles in refugee integration into a theoretical framework founded on Dervin's sense-making methodology.;The research data were collected by interviews and observations, such that the observation data substantiated interview findings. A diverse population of refugees were interviewed directly and observation of service provision was recorded during a volunteer role with the Scottish Refugee Council. The data analysis was process-driven and dynamic, using an iterative process of thematic coding. This resulted in pertinent institutional dimensions being factored into the identification of information needs.;The research findings culminated in an information needs matrix - a navigational guide with implications for research, policy and practice. The study found connections between people, information and sociological needs as refugees navigate integration processes and systems. In addition, the experiences of navigating integration systems were tied to specific times, places and human conditions. This relationship resulted in the information needs matrix, which encompasses the complexities of navigating integration systems and points to refugee integration being as much an information issue as it is a sociological one.This thesis reports on an information behaviour investigation into refugee integration, undertaken to understand how refugees navigate complex integration processes and systems. The aim was to find person-centred information needs, relationships and sources that could inform the design of person-centred integration systems. The study was carried out through an interdisciplinary synthesis of academic literatures and professional practice. Theories of information behaviour were synthesised with principles in refugee integration into a theoretical framework founded on Dervin's sense-making methodology.;The research data were collected by interviews and observations, such that the observation data substantiated interview findings. A diverse population of refugees were interviewed directly and observation of service provision was recorded during a volunteer role with the Scottish Refugee Council. The data analysis was process-driven and dynamic, using an iterative process of thematic coding. This resulted in pertinent institutional dimensions being factored into the identification of information needs.;The research findings culminated in an information needs matrix - a navigational guide with implications for research, policy and practice. The study found connections between people, information and sociological needs as refugees navigate integration processes and systems. In addition, the experiences of navigating integration systems were tied to specific times, places and human conditions. This relationship resulted in the information needs matrix, which encompasses the complexities of navigating integration systems and points to refugee integration being as much an information issue as it is a sociological one
Bioactive phytochemicals from Libyan medicinal plants : Cynara cyrenaica Maire & Weill and Cyclamen rohlfsianum Aschers
Get PDFMedicinal plants have a long history in the treatment of diseases. Studies on phytochemicals from medicinal plants have continued to increase due to their importance in the search for new drugs. The El-Jabal El-Akhdar region (Green Mountain) of Libya has a high diversity of medicinal plants which are presently poorly studied. This dissertation describes studies on Cynara cyrenaica and Cyclamen rohlfsianum, collected from the region, for phytochemical, anticancer and antidiabetic evaluation. The phytochemical evaluation revealed one saponin 3-O-{β-D-xylopyranosyl-(12)-β-D-glucopyranosyl-(14)-[β-D-glucopyranosyl-(12)]-α-L-arabinopyranosyl}-cyclamiretin A (CY1) isolated from C. rohlfsianum. Thirteen compounds were isolated from C. cyrenaica, including two identified as novel sesquiterpene lactones named 3β-hydroxy-8α-[(S)-4-hydroxy-3- methylbutanyloxy]-guaian-4(15), 10(14), 11(13)-trien-1α, 5α, 7α, 6βH-12, 6-olide (CC12) and 11, 13 epoxy-guaian-4(15), 10(14)-dien-1α, 5α, 7α, 6βH-12, 6-olide-3-yl acetate (CC13). The other compounds were taraxasterol, pseudotaraxasterol, ll,13-epoxysolstitialin (CC5), apigenin, luteolin-7-O-β-D-glucopyranoside, luteolin, catechin 7-O-gallate, ferulic acid, 1, 3-dicaffeoylquinic acid, daucosterol and 1-monoacetyl glycerol. A preliminary in vitro antidiabetic assessment of all crude solvent extracts and most of the isolated compounds was carried out using α-glucosidase, protein tyrosine phosphatase 1B (PTP1B) and α-amylase inhibition tests. For α-glucosidase, only catechin 7-O-gallate from C. cyrenaica was found to be active with significant (p < 0.001) inhibition and produced concentration-dependent inhibition with an IC50 value of 3.94 ± 1.1μM. For the C. rohlfsianum tuber, the crude methanol extract and CY1 isolated from this extract produced marked inhibitory activity on α-glucosidase with IC50 values of 3.46 ± 1.13μg/ml and 5.53 ± 1.1μM, respectively. For PTP1B assay only luteolin from C. cyrenaica was found to be significantly (p < 0.001) active and showed dose-dependent inhibition activity with an IC50 value of 15.94 ± 1.12μM. In an α-amylase assay, no inhibition of the enzyme was produced by both plants. These findings provide some scientific support for the traditional use of this plant as an anti-diabetic. The crude solvent extracts and some of the isolated compounds were also screened in vitro for cytotoxicity against human cancer cell lines: A375 (malignant melanoma), PANC-1 (pancreatic carcinoma), and HeLa (cervical cancer) in comparison with a non-cancer PNT2 cell line (prostate cell line) using an AlamarBlue® assay. Among the crude solvent extracts tested, the n-hexane and ethyl acetate extract of C. cyrenaica flower heads showed inhibition of metabolic activity on all the cell lines, including the PNT2 cells, but those of the ethyl acetate extract of the root, leaf and stem were the most potent against PANC-1 cells with IC50 values of 2.73 ± 1.18, 0.004 ± 1.02 and 1.40 ± 1.87μg/ml, respectively and showed inhibition effect on PNT2 cells with different ranges of IC50. For the ethyl acetate extracts of C. cyrenaica root and stem this effect could be linked in part to the presence of sesquiterpene lactones (CC5, CC12 and C13). Furthermore, the n-hexane extract of C. cyrenaica leaf also showed inhibitory metabolic activity in HeLa and PANC-1 cells at 25μg/ml and showed inhibition effect on PNT2 cells with IC50 value of 10.71 ± 1.30μg/ml. For the C. rohlfsianum tuber, the only inhibition was observed with the methanol extract on all the cell lines, including the PNT2 cells with an IC50 value of 3.16 ± 1.08μg/ml for PNT2 and 6.35 ± 1.09, 42.37 ± 1.13 and 4.19 ± 1.11μg/ml for A375, HeLa and PANC-1, respectively. Among the screened compounds, taraxasterol showed selective activity against HeLa cells with no toxic effect on normal cells. While luteolin, ll, 13-epoxysolstitialin, CY1 and CC12 were active against all the cancer cell lines. However, ll, 13-epoxysolstitialin was potent against PANC-1 cells with an IC50 value of 4.70 ± 1.06μM, while CC12 showed marked inhibitory effect on PANC-1 cells with an IC50 value of 24.43 ± 1.32μM. Both compounds were then tested for their ability to prevent metastatic dissemination of PANC-1 cells using the following kits: CytoselectTM 48-well Adhesion Assays (collagen IV and fibronectin), Poly-L-lysine Adhesion Assay, InnoCyteTM Cell Migration Assay and InnoCyteTM Cell Invasion Assay. The results revealed that both compounds inhibited adhesion, migration and invasion of PANC-1 cancer cells. These findings, although preliminary, propose a new potential therapeutic use of C. cyrenaica and C. rohlfsianum which could lead to the discovery of potent agents for the treatment of pancreatic carcinoma and diabetes.Medicinal plants have a long history in the treatment of diseases. Studies on phytochemicals from medicinal plants have continued to increase due to their importance in the search for new drugs. The El-Jabal El-Akhdar region (Green Mountain) of Libya has a high diversity of medicinal plants which are presently poorly studied. This dissertation describes studies on Cynara cyrenaica and Cyclamen rohlfsianum, collected from the region, for phytochemical, anticancer and antidiabetic evaluation. The phytochemical evaluation revealed one saponin 3-O-{β-D-xylopyranosyl-(12)-β-D-glucopyranosyl-(14)-[β-D-glucopyranosyl-(12)]-α-L-arabinopyranosyl}-cyclamiretin A (CY1) isolated from C. rohlfsianum. Thirteen compounds were isolated from C. cyrenaica, including two identified as novel sesquiterpene lactones named 3β-hydroxy-8α-[(S)-4-hydroxy-3- methylbutanyloxy]-guaian-4(15), 10(14), 11(13)-trien-1α, 5α, 7α, 6βH-12, 6-olide (CC12) and 11, 13 epoxy-guaian-4(15), 10(14)-dien-1α, 5α, 7α, 6βH-12, 6-olide-3-yl acetate (CC13). The other compounds were taraxasterol, pseudotaraxasterol, ll,13-epoxysolstitialin (CC5), apigenin, luteolin-7-O-β-D-glucopyranoside, luteolin, catechin 7-O-gallate, ferulic acid, 1, 3-dicaffeoylquinic acid, daucosterol and 1-monoacetyl glycerol. A preliminary in vitro antidiabetic assessment of all crude solvent extracts and most of the isolated compounds was carried out using α-glucosidase, protein tyrosine phosphatase 1B (PTP1B) and α-amylase inhibition tests. For α-glucosidase, only catechin 7-O-gallate from C. cyrenaica was found to be active with significant (p < 0.001) inhibition and produced concentration-dependent inhibition with an IC50 value of 3.94 ± 1.1μM. For the C. rohlfsianum tuber, the crude methanol extract and CY1 isolated from this extract produced marked inhibitory activity on α-glucosidase with IC50 values of 3.46 ± 1.13μg/ml and 5.53 ± 1.1μM, respectively. For PTP1B assay only luteolin from C. cyrenaica was found to be significantly (p < 0.001) active and showed dose-dependent inhibition activity with an IC50 value of 15.94 ± 1.12μM. In an α-amylase assay, no inhibition of the enzyme was produced by both plants. These findings provide some scientific support for the traditional use of this plant as an anti-diabetic. The crude solvent extracts and some of the isolated compounds were also screened in vitro for cytotoxicity against human cancer cell lines: A375 (malignant melanoma), PANC-1 (pancreatic carcinoma), and HeLa (cervical cancer) in comparison with a non-cancer PNT2 cell line (prostate cell line) using an AlamarBlue® assay. Among the crude solvent extracts tested, the n-hexane and ethyl acetate extract of C. cyrenaica flower heads showed inhibition of metabolic activity on all the cell lines, including the PNT2 cells, but those of the ethyl acetate extract of the root, leaf and stem were the most potent against PANC-1 cells with IC50 values of 2.73 ± 1.18, 0.004 ± 1.02 and 1.40 ± 1.87μg/ml, respectively and showed inhibition effect on PNT2 cells with different ranges of IC50. For the ethyl acetate extracts of C. cyrenaica root and stem this effect could be linked in part to the presence of sesquiterpene lactones (CC5, CC12 and C13). Furthermore, the n-hexane extract of C. cyrenaica leaf also showed inhibitory metabolic activity in HeLa and PANC-1 cells at 25μg/ml and showed inhibition effect on PNT2 cells with IC50 value of 10.71 ± 1.30μg/ml. For the C. rohlfsianum tuber, the only inhibition was observed with the methanol extract on all the cell lines, including the PNT2 cells with an IC50 value of 3.16 ± 1.08μg/ml for PNT2 and 6.35 ± 1.09, 42.37 ± 1.13 and 4.19 ± 1.11μg/ml for A375, HeLa and PANC-1, respectively. Among the screened compounds, taraxasterol showed selective activity against HeLa cells with no toxic effect on normal cells. While luteolin, ll, 13-epoxysolstitialin, CY1 and CC12 were active against all the cancer cell lines. However, ll, 13-epoxysolstitialin was potent against PANC-1 cells with an IC50 value of 4.70 ± 1.06μM, while CC12 showed marked inhibitory effect on PANC-1 cells with an IC50 value of 24.43 ± 1.32μM. Both compounds were then tested for their ability to prevent metastatic dissemination of PANC-1 cells using the following kits: CytoselectTM 48-well Adhesion Assays (collagen IV and fibronectin), Poly-L-lysine Adhesion Assay, InnoCyteTM Cell Migration Assay and InnoCyteTM Cell Invasion Assay. The results revealed that both compounds inhibited adhesion, migration and invasion of PANC-1 cancer cells. These findings, although preliminary, propose a new potential therapeutic use of C. cyrenaica and C. rohlfsianum which could lead to the discovery of potent agents for the treatment of pancreatic carcinoma and diabetes
Bullying in secure settings : a mixed method study in Malaysian juvenile justice institutions
Get PDFThis thesis investigates bullying and victimisation in juvenile justice institutions. It examines the role of personal characteristics and aspects of institutional environments, and explores how these factors relate to bullying behaviour. The research collected quantitative and qualitative data using a mixed-method approach. The study comprised a survey completed by 289 male and female young people, aged 12 to 21 years old, in 8 juvenile justice institutions, using the scale version of Direct and Indirect Prisoner behaviour Checklist (DIPC‐SCALEDr) and Measuring the Quality of Prison life (MQPL) instruments. In addition, 24 interviews were carried out with 16 young people and 8 institutional staff, comprising both male and female participants. The findings showed that 95 percent of young people reported at least one behaviour indicative of bullying others, and 99 percent reported at least one behaviour indicative of victimisation in a month. The DIPC‐SCALEDr scored significantly higher on verbal forms of bullying and victimisation than psychological, physical, sexual, theft‐related and indirect forms. In addition, eight predictors are found to underpin bullying behaviour, including four personal characteristics i.e. time spent in the institution; experiences of punishment inside the institution; gang membership; and no self-harm ; and four institutional dimensions i.e respect; bureaucratic legitimacy; fairness; and family contact. In the interviews, young people and staff members identified four functions underpinning aggressive behaviour in the institution, including 'protecting oneself from threatening events', 'exerting control over others', 'access to goods' and 'building alliances'. Furthermore, young people and staff members identified eight predictors that influenced their choices and decisions in bullying others. The strong desire to protect and enhance one's sense of power and self-worth underpins illegitimate coping such as bullying others. In contrast, perceived negative outcomes of bullying conduct decreased an individual's likelihood of bullying others. To conclude, bullying behaviour seemed to be normalized in juvenile justice institutions.This thesis investigates bullying and victimisation in juvenile justice institutions. It examines the role of personal characteristics and aspects of institutional environments, and explores how these factors relate to bullying behaviour. The research collected quantitative and qualitative data using a mixed-method approach. The study comprised a survey completed by 289 male and female young people, aged 12 to 21 years old, in 8 juvenile justice institutions, using the scale version of Direct and Indirect Prisoner behaviour Checklist (DIPC‐SCALEDr) and Measuring the Quality of Prison life (MQPL) instruments. In addition, 24 interviews were carried out with 16 young people and 8 institutional staff, comprising both male and female participants. The findings showed that 95 percent of young people reported at least one behaviour indicative of bullying others, and 99 percent reported at least one behaviour indicative of victimisation in a month. The DIPC‐SCALEDr scored significantly higher on verbal forms of bullying and victimisation than psychological, physical, sexual, theft‐related and indirect forms. In addition, eight predictors are found to underpin bullying behaviour, including four personal characteristics i.e. time spent in the institution; experiences of punishment inside the institution; gang membership; and no self-harm ; and four institutional dimensions i.e respect; bureaucratic legitimacy; fairness; and family contact. In the interviews, young people and staff members identified four functions underpinning aggressive behaviour in the institution, including 'protecting oneself from threatening events', 'exerting control over others', 'access to goods' and 'building alliances'. Furthermore, young people and staff members identified eight predictors that influenced their choices and decisions in bullying others. The strong desire to protect and enhance one's sense of power and self-worth underpins illegitimate coping such as bullying others. In contrast, perceived negative outcomes of bullying conduct decreased an individual's likelihood of bullying others. To conclude, bullying behaviour seemed to be normalized in juvenile justice institutions
The initiation of electric arcs and the possible impact in industrial environments
Get PDFAdvancing knowledge and understanding of electrical arc flash and arc blast hazards through experimentation, modelling and analysis is the main goal of the present thesis. To achieve this, initially, significant work has been carried out to analyse existing data on arc flash hazards and mitigation engineering practices in industrial premises. Then, experimental investigations on the electrical arc characteristics have been conducted which together with the development of an analytical model for quantification of arc's energy components have formed the core of the research project.;Electrical characteristics of the initial stage of the arc have been obtained experimentally using different test systems developed in the course of this study. Two different arc initiation mechanisms have been examined: self-breakdown spark gap (SBSG) and wire-guided spark gap (WGSG) discharge initiation. Data post-processing techniques have been developed to obtain arc voltage and current waveforms for calculating the electrical arc energy available in the discharge.;An analytical model has been developed based on the hydrodynamic approach, to further analyse the energy dissipated and to obtain the energy components associated with thermal, acoustic-kinetic and light emission processes. This analysis of the energy components provides data for safety considerations which are currently not taken into account by the existing standards. Furthermore, analysis and evaluation of the suitability of black-box models for predicting the arc characteristics during its initiation taking into account electric circuit parameters have been performed.;Initial conditions for analysis of the ratio of the arc current over voltage have been obtained from experimental waveforms to investigate the arc-electrical circuit interaction. This can be considered as a first step towards establishment of a complete accurate link between the microscale and macroscale manifestation of the arc flash and arc blast phenomena. It is envisaged that further understanding of the complex energy conversion processes taking place in the post-arc-initiation process can provide additional tools for quantifying arc energy components and improving arc flash and arc blast safety.Advancing knowledge and understanding of electrical arc flash and arc blast hazards through experimentation, modelling and analysis is the main goal of the present thesis. To achieve this, initially, significant work has been carried out to analyse existing data on arc flash hazards and mitigation engineering practices in industrial premises. Then, experimental investigations on the electrical arc characteristics have been conducted which together with the development of an analytical model for quantification of arc's energy components have formed the core of the research project.;Electrical characteristics of the initial stage of the arc have been obtained experimentally using different test systems developed in the course of this study. Two different arc initiation mechanisms have been examined: self-breakdown spark gap (SBSG) and wire-guided spark gap (WGSG) discharge initiation. Data post-processing techniques have been developed to obtain arc voltage and current waveforms for calculating the electrical arc energy available in the discharge.;An analytical model has been developed based on the hydrodynamic approach, to further analyse the energy dissipated and to obtain the energy components associated with thermal, acoustic-kinetic and light emission processes. This analysis of the energy components provides data for safety considerations which are currently not taken into account by the existing standards. Furthermore, analysis and evaluation of the suitability of black-box models for predicting the arc characteristics during its initiation taking into account electric circuit parameters have been performed.;Initial conditions for analysis of the ratio of the arc current over voltage have been obtained from experimental waveforms to investigate the arc-electrical circuit interaction. This can be considered as a first step towards establishment of a complete accurate link between the microscale and macroscale manifestation of the arc flash and arc blast phenomena. It is envisaged that further understanding of the complex energy conversion processes taking place in the post-arc-initiation process can provide additional tools for quantifying arc energy components and improving arc flash and arc blast safety
High-voltage pulse generators incorporating modular multilevel converter sub-modules
Get PDFRecent research established the effectiveness of applying a pulsed electric field to deactivate harmful microorganisms (such as bacteria and E. coli). Successful deactivation is achieved by lethal electroporation; a process that produces electric pores in the biological cell membrane of the harmful microorganisms when subjected to high-voltage (HV) pulses. The HV pulses are designed to create pores beyond a critical size at which the biological cell can reseal.;In contrast when applying non-lethal electroporation, the cell-membrane survives after the electroporation process. This is required, for example, when inserting protein cells in the cell-membrane. In both lethal and non-lethal electroporation, HV pulses in the kilo-Volt range (1-100 kV) with durations ranging between nanoseconds and milliseconds are required.;This thesis proposes nine pulse generator (PG) topologies based on power electronic devices and modular multilevel converter sub-modules. The proposed topologies are divided into two main groups namely: PGs fed from a HV DC supply and PGs fed from an LV DC supply. The first group presents a new family of HV DC fed topologies that improve the performance of existing HV DC fed PGs, such as flexible pulse-waveform generation and full utilisation of the DC link voltage.;The second group is dedicated to a new family of LV DC fed PG topologies which have flexible pulse-waveform generation, controlled operation efficiency, and high voltage gain.;All the proposed PG topologies share the important aspect in the newly developed HV PGs, that is modularity, which offers redundancy and robust pulse generation operation.;The presented PG topologies are supported by theoretical analysis, simulations, and experimentation.Recent research established the effectiveness of applying a pulsed electric field to deactivate harmful microorganisms (such as bacteria and E. coli). Successful deactivation is achieved by lethal electroporation; a process that produces electric pores in the biological cell membrane of the harmful microorganisms when subjected to high-voltage (HV) pulses. The HV pulses are designed to create pores beyond a critical size at which the biological cell can reseal.;In contrast when applying non-lethal electroporation, the cell-membrane survives after the electroporation process. This is required, for example, when inserting protein cells in the cell-membrane. In both lethal and non-lethal electroporation, HV pulses in the kilo-Volt range (1-100 kV) with durations ranging between nanoseconds and milliseconds are required.;This thesis proposes nine pulse generator (PG) topologies based on power electronic devices and modular multilevel converter sub-modules. The proposed topologies are divided into two main groups namely: PGs fed from a HV DC supply and PGs fed from an LV DC supply. The first group presents a new family of HV DC fed topologies that improve the performance of existing HV DC fed PGs, such as flexible pulse-waveform generation and full utilisation of the DC link voltage.;The second group is dedicated to a new family of LV DC fed PG topologies which have flexible pulse-waveform generation, controlled operation efficiency, and high voltage gain.;All the proposed PG topologies share the important aspect in the newly developed HV PGs, that is modularity, which offers redundancy and robust pulse generation operation.;The presented PG topologies are supported by theoretical analysis, simulations, and experimentation
Professionalisation, entrepreneurial orientation and employee engagement in family and non family firms : a study of graduate employees in Indonesia
Get PDFEmployee engagement is essential for both employee and business outcomes. For example, research suggests that employee engagement can encourage employee retention and boost profitability. Recent trends, however, depict a decline in levels of employee engagement with differences further observed between family and nonfamily firms. Using a sample of 545 highly educated Indonesian employees, this thesis employs Structural Equation Modelling to examine the potential effects of firm professionalisation and Entrepreneurial Orientation (EO) factors on employee engagement in family and nonfamily firms.;This thesis finds that professionalisation and EO are not dichotomous, but may mutually promote employee engagement. Drawing on the Personal Engagement Concept (PEC) and Social Exchange Theory (SET), the study posits that professionalisation provides predictability, transparency and perceived justice to compensate for any uncertainty that may be attached to the entrepreneurial firm. Equally, entrepreneurial behaviour provides challenging and stimulating work to compensate for inflexibility that may be attached to the professionalised firm. These dynamics together enhance employee engagement.;The positive impact of professionalisation and EO factors on employee engagement is however lower in family firms. This may be due to the typical family firm behaviours, such as self-control, dual-roles, and altruism, that could interfere with formal business procedures and reduce employee perceptions of predictability, transparency and justice. In particular, family firm owners' dual roles may reduce employee involvement in decision-making processes, thereby discouraging employee creativity.;To effectively encourage employee engagement, this thesis therefore proposes that both family and nonfamily firms should heed the various human resource aspects of professionalisation. For family firms, in particular, since natural nepotism and subjective decisions could undermine any formal authority bestowed upon employees in family firms, installing formal recruitment procedures, performance reviews, training, and performance-based pay is recommended as a more effective strategy to boost employee engagement.Employee engagement is essential for both employee and business outcomes. For example, research suggests that employee engagement can encourage employee retention and boost profitability. Recent trends, however, depict a decline in levels of employee engagement with differences further observed between family and nonfamily firms. Using a sample of 545 highly educated Indonesian employees, this thesis employs Structural Equation Modelling to examine the potential effects of firm professionalisation and Entrepreneurial Orientation (EO) factors on employee engagement in family and nonfamily firms.;This thesis finds that professionalisation and EO are not dichotomous, but may mutually promote employee engagement. Drawing on the Personal Engagement Concept (PEC) and Social Exchange Theory (SET), the study posits that professionalisation provides predictability, transparency and perceived justice to compensate for any uncertainty that may be attached to the entrepreneurial firm. Equally, entrepreneurial behaviour provides challenging and stimulating work to compensate for inflexibility that may be attached to the professionalised firm. These dynamics together enhance employee engagement.;The positive impact of professionalisation and EO factors on employee engagement is however lower in family firms. This may be due to the typical family firm behaviours, such as self-control, dual-roles, and altruism, that could interfere with formal business procedures and reduce employee perceptions of predictability, transparency and justice. In particular, family firm owners' dual roles may reduce employee involvement in decision-making processes, thereby discouraging employee creativity.;To effectively encourage employee engagement, this thesis therefore proposes that both family and nonfamily firms should heed the various human resource aspects of professionalisation. For family firms, in particular, since natural nepotism and subjective decisions could undermine any formal authority bestowed upon employees in family firms, installing formal recruitment procedures, performance reviews, training, and performance-based pay is recommended as a more effective strategy to boost employee engagement
'A different existence altogether' constructing, conditioning and controlling the British soldier's body in the First World War
Get PDFThis thesis examines the processes by which British male civilians became soldiers during the First World War. It contributes to the historiography on the British experience of the war by placing the human body at the centre of the analysis and considering the impact of bodies under the control and care of the British Army. It expands upon the sociological literature of 'the body' by establishing how these theoretical concepts are evident within the empirical research.;Through an analysis of official records and publications, it explores how the state sought to transform the male civilian body for military purposes. A significant aspect of this research stems from the personal experiences of the men who served by painstaking consideration of their letters, diaries, and oral testimonies.;This research illustrates that the body was a core concern for the British military as well as being central in perceptions of physical worth within British society during the First World War. Between 1914-1918 British men's bodies were assessed, categorised, improved, damaged, recovered, repaired and destroyed. From enlistment to the end of service, soldier's bodies were repurposed for the pursuit of victory as the British military and the government focused on constructing, conditioning and controlling the bodies of regular, territorial, volunteer and conscript soldiers.;In a letter to his mother, Lieutenant Godfrey classified the war as a 'different existence altogether' and indeed it was for many men whose bodies became fitter, healthier, and more skilled, while paradoxically also allowing them to resist military control, be wounded, harm their own bodies, and die. This work, therefore, explores the male military body within the chaos of the First World War, not simply as a faceless man in uniform but an individual whose body was a site of conflict focused on agency, indoctrination and military service.This thesis examines the processes by which British male civilians became soldiers during the First World War. It contributes to the historiography on the British experience of the war by placing the human body at the centre of the analysis and considering the impact of bodies under the control and care of the British Army. It expands upon the sociological literature of 'the body' by establishing how these theoretical concepts are evident within the empirical research.;Through an analysis of official records and publications, it explores how the state sought to transform the male civilian body for military purposes. A significant aspect of this research stems from the personal experiences of the men who served by painstaking consideration of their letters, diaries, and oral testimonies.;This research illustrates that the body was a core concern for the British military as well as being central in perceptions of physical worth within British society during the First World War. Between 1914-1918 British men's bodies were assessed, categorised, improved, damaged, recovered, repaired and destroyed. From enlistment to the end of service, soldier's bodies were repurposed for the pursuit of victory as the British military and the government focused on constructing, conditioning and controlling the bodies of regular, territorial, volunteer and conscript soldiers.;In a letter to his mother, Lieutenant Godfrey classified the war as a 'different existence altogether' and indeed it was for many men whose bodies became fitter, healthier, and more skilled, while paradoxically also allowing them to resist military control, be wounded, harm their own bodies, and die. This work, therefore, explores the male military body within the chaos of the First World War, not simply as a faceless man in uniform but an individual whose body was a site of conflict focused on agency, indoctrination and military service
The influence of matrix stoichiometry on interfacial adhesion in composites for wind turbine applications
Get PDFIt is well known that the fibre-matrix interface plays a key role in defining the mechanical properties of fibre composite materials. The ability to efficiently transfer stress between the matrix and the fibres is critical in ensuring the required performance level needed for advanced composite materials. Stress transfer across the fibre-matrix interface is often reduced to a discussion of 'adhesion'. Past discussions of thermosetting matrices have typically focussed on the chemistry of thematrix system, specifically the task of maximising the level of chemical bonding between the fibre and the matrix to produce the strongest interface. However, many authors have also commented on the potential for residual radial compressive stresses formed at the interface to be a significant contributor to the strength of the interface. There is still a significant weight of opinion that holds that even if these residual stresses at the interface can contribute to the stress transfer capability, then chemistry and chemical reactions must play an active role in defining their magnitude. As such it was the objective of this thesis to develop an understanding of how chemistry and residual stresses formed at the interface could be interrelated to influence the stress transfer capability of the interface. First an understanding was established of how the amine-to-epoxy group ratio (R) of an amine cured epoxy influences the thermomechanical properties of the matrix. Overall it was shown that the R value had a major influence over all of the thermomechanical properties studied. The glass transition temperature (Tg) was shown to change significantly depending on the R value, with a maximum of 87.3 °C observed at a value (R [approx. equal to] 1.25) slightly above the stoichiometric point. The matrix Tg decreased as the R value deviated from this value, approaching room temperature for the extreme ratios. Above Tg, the linear coefficient of thermal expansion (LCTE) was shown to reach a minimum at the stoichiometric ratio due to this ratio inducing the highest crosslink density. Below Tg, the R value appeared to have a less clear influence. The storage modulus (E') of the matrix was also shown to be affected by the R value, with the stoichiometric ratio possessing the largest magnitude of E' for temperatures 20°C above Tg. However, for temperatures 20 °C below Tg the storage modulus decreased in magnitude the closer the R value was to R [approx. equal to] 1.25.;This was the ratio measured to possess the largest Tg value and thus the highest temperature at which E' was plotted relative to the other ratios. The effect of changing the R value on the interfacial shear strength (IFSS) was investigated using the microbond test. This was done in combination with changing the surface chemistry of the glass fibre and purity of the hardener. Results showed the magnitude of IFSS to be significantly affected by the R value, independent of the fibre sizing applied. The chemistry of the fibre sizing was shown to influence the maximum IFSS achievable and the R value at which it would occur, however the magnitude differences were not as significant. From these results it was concluded that the R value of the matrix has a greater influence than the chemistry of the fibre sizing in defining the level of adhesion at the fibre-matrix interface. The changes in IFSS were shown to correlate with Tg and the decrease in the contribution of residual thermal stresses at the interface. However, this contribution only represented a portion of the total IFSS value measured. It was concluded that other mechanisms, such as cure shrinkage stresses, must provide the remaining portion of IFSS shown. To expand upon this, the influence of temperature in combination with the other variables discussed was studied using the microbond test within a thermomechanical analyser. At lower temperatures the maximum IFSS value was shown to occur at R [approx. equal to] 1.0. The magnitude of IFSS was then shown to decrease as the R value deviated further from this value, again independent of the chemistry of the fibre sizing. Above Tg it was observed that a small value of IFSS remained which appeared to possess a linear relationship with the level of amine present within the Rratio. It was hypothesized that the magnitude of IFSS being greater for excess amineratios (R > 1) resulted from a combination of an increase in the level of hydrogen bonding and a variation in the shear failure behaviour of the matrix due to the differing crosslink densities.;Using Nairn's model, a correlation was shown to exist between the IFSS values measured and the potential total contribution of residual stresses for R [approx. equal to] 1.0. However, as the ratios deviated further from R [approx. equal to] 1.0 the degree of correlation was shown to decrease. It was concluded that assumptions made by the model regarding the contribution of cure shrinkage stresses appeared to be oversimplifications once the R value deviated significantly from R [approx. equal to] 1.0. To address this a novel technique using hot-stage microscopy was used to measure the cure shrinkage of a minute epoxy droplet upon a single fibre during the curing process. The results showed that as the R value was increased, the level of cure shrinkage increased. Rheometry was then used to study the influence of the R value on the gel time of the matrix and applied to the data collected using the hot-stage method. This cure shrinkage data was then reapplied to the model where again good correlation was shown for R [approx. equal to] 1.0, yet the discrepancies regarding off-stoichiometric ratios remained. It was concluded that this may be due to a lack of understanding regarding the Tg of a microdroplet and the adhesion mechanisms of a rubbery statepolymer. Overall it was concluded that Nairn's model supports the hypothesis that residual radial compressive stresses at the interface can contribute significantly to the stress transfer capability of the interface. Since these stresses were shown to be affected by the R value it would also satisfy the need for chemistry to be involved significantly in some role.It is well known that the fibre-matrix interface plays a key role in defining the mechanical properties of fibre composite materials. The ability to efficiently transfer stress between the matrix and the fibres is critical in ensuring the required performance level needed for advanced composite materials. Stress transfer across the fibre-matrix interface is often reduced to a discussion of 'adhesion'. Past discussions of thermosetting matrices have typically focussed on the chemistry of thematrix system, specifically the task of maximising the level of chemical bonding between the fibre and the matrix to produce the strongest interface. However, many authors have also commented on the potential for residual radial compressive stresses formed at the interface to be a significant contributor to the strength of the interface. There is still a significant weight of opinion that holds that even if these residual stresses at the interface can contribute to the stress transfer capability, then chemistry and chemical reactions must play an active role in defining their magnitude. As such it was the objective of this thesis to develop an understanding of how chemistry and residual stresses formed at the interface could be interrelated to influence the stress transfer capability of the interface. First an understanding was established of how the amine-to-epoxy group ratio (R) of an amine cured epoxy influences the thermomechanical properties of the matrix. Overall it was shown that the R value had a major influence over all of the thermomechanical properties studied. The glass transition temperature (Tg) was shown to change significantly depending on the R value, with a maximum of 87.3 °C observed at a value (R [approx. equal to] 1.25) slightly above the stoichiometric point. The matrix Tg decreased as the R value deviated from this value, approaching room temperature for the extreme ratios. Above Tg, the linear coefficient of thermal expansion (LCTE) was shown to reach a minimum at the stoichiometric ratio due to this ratio inducing the highest crosslink density. Below Tg, the R value appeared to have a less clear influence. The storage modulus (E') of the matrix was also shown to be affected by the R value, with the stoichiometric ratio possessing the largest magnitude of E' for temperatures 20°C above Tg. However, for temperatures 20 °C below Tg the storage modulus decreased in magnitude the closer the R value was to R [approx. equal to] 1.25.;This was the ratio measured to possess the largest Tg value and thus the highest temperature at which E' was plotted relative to the other ratios. The effect of changing the R value on the interfacial shear strength (IFSS) was investigated using the microbond test. This was done in combination with changing the surface chemistry of the glass fibre and purity of the hardener. Results showed the magnitude of IFSS to be significantly affected by the R value, independent of the fibre sizing applied. The chemistry of the fibre sizing was shown to influence the maximum IFSS achievable and the R value at which it would occur, however the magnitude differences were not as significant. From these results it was concluded that the R value of the matrix has a greater influence than the chemistry of the fibre sizing in defining the level of adhesion at the fibre-matrix interface. The changes in IFSS were shown to correlate with Tg and the decrease in the contribution of residual thermal stresses at the interface. However, this contribution only represented a portion of the total IFSS value measured. It was concluded that other mechanisms, such as cure shrinkage stresses, must provide the remaining portion of IFSS shown. To expand upon this, the influence of temperature in combination with the other variables discussed was studied using the microbond test within a thermomechanical analyser. At lower temperatures the maximum IFSS value was shown to occur at R [approx. equal to] 1.0. The magnitude of IFSS was then shown to decrease as the R value deviated further from this value, again independent of the chemistry of the fibre sizing. Above Tg it was observed that a small value of IFSS remained which appeared to possess a linear relationship with the level of amine present within the Rratio. It was hypothesized that the magnitude of IFSS being greater for excess amineratios (R > 1) resulted from a combination of an increase in the level of hydrogen bonding and a variation in the shear failure behaviour of the matrix due to the differing crosslink densities.;Using Nairn's model, a correlation was shown to exist between the IFSS values measured and the potential total contribution of residual stresses for R [approx. equal to] 1.0. However, as the ratios deviated further from R [approx. equal to] 1.0 the degree of correlation was shown to decrease. It was concluded that assumptions made by the model regarding the contribution of cure shrinkage stresses appeared to be oversimplifications once the R value deviated significantly from R [approx. equal to] 1.0. To address this a novel technique using hot-stage microscopy was used to measure the cure shrinkage of a minute epoxy droplet upon a single fibre during the curing process. The results showed that as the R value was increased, the level of cure shrinkage increased. Rheometry was then used to study the influence of the R value on the gel time of the matrix and applied to the data collected using the hot-stage method. This cure shrinkage data was then reapplied to the model where again good correlation was shown for R [approx. equal to] 1.0, yet the discrepancies regarding off-stoichiometric ratios remained. It was concluded that this may be due to a lack of understanding regarding the Tg of a microdroplet and the adhesion mechanisms of a rubbery statepolymer. Overall it was concluded that Nairn's model supports the hypothesis that residual radial compressive stresses at the interface can contribute significantly to the stress transfer capability of the interface. Since these stresses were shown to be affected by the R value it would also satisfy the need for chemistry to be involved significantly in some role
A data analytic approach to automatic fault diagnosis and prognosis for distribution automation
Get PDFDistribution Automation (DA) is deployed to reduce outages and to rapidly reconnect customers following network faults. Recent developments in DA equipment have enabled the logging of load and fault event data, referred to as pick-up activity. This pick-up activity provides a picture of the underlying circuit activity occurring between successive DA operations over a period of time and has the potential to be accessed remotely for off-line or on-line analysis. The application of data analytics and automated analysis of this data supports reactive fault management and post fault investigation into anomalous network behavior. It also supports predictive capabilities that identify when potential network faults are evolving and offers the opportunity to take action in advance in order to mitigate any outages.This thesis details the design of a novel decision support system to achieve automatic fault diagnosis and prognosis for DA schemes. It combines detailed data from a specific DA device with SCADA data, by utilising rule-based, data science techniques (e.g. data mining and clustering techniques) to deliver the diagnostic and prognostic functions. These are applied to 11kV distribution network data captured from Pole Mounted Auto-Reclosers (PMARs) as provided by a leading UK network operator. This novel automated analysis system diagnoses the condition of device faults, the nature of a circuit's previous fault activity, identifies underlying anomalous circuit activity, and highlights indications of problematic events gradually evolving into a full scale circuit fault using prognostic functionality. The novel contributions also include the characterisation and identification of semi-permanent faults and a re-usable methodology and approach for applying data analytics to any DA device data sets in order to provide diagnostic decisions and mitigate potential fault scenarios.Distribution Automation (DA) is deployed to reduce outages and to rapidly reconnect customers following network faults. Recent developments in DA equipment have enabled the logging of load and fault event data, referred to as pick-up activity. This pick-up activity provides a picture of the underlying circuit activity occurring between successive DA operations over a period of time and has the potential to be accessed remotely for off-line or on-line analysis. The application of data analytics and automated analysis of this data supports reactive fault management and post fault investigation into anomalous network behavior. It also supports predictive capabilities that identify when potential network faults are evolving and offers the opportunity to take action in advance in order to mitigate any outages.This thesis details the design of a novel decision support system to achieve automatic fault diagnosis and prognosis for DA schemes. It combines detailed data from a specific DA device with SCADA data, by utilising rule-based, data science techniques (e.g. data mining and clustering techniques) to deliver the diagnostic and prognostic functions. These are applied to 11kV distribution network data captured from Pole Mounted Auto-Reclosers (PMARs) as provided by a leading UK network operator. This novel automated analysis system diagnoses the condition of device faults, the nature of a circuit's previous fault activity, identifies underlying anomalous circuit activity, and highlights indications of problematic events gradually evolving into a full scale circuit fault using prognostic functionality. The novel contributions also include the characterisation and identification of semi-permanent faults and a re-usable methodology and approach for applying data analytics to any DA device data sets in order to provide diagnostic decisions and mitigate potential fault scenarios
Non-thermal plasma for water treatment
Get PDFPlasma generated in contact with water has been extensively investigated in various electrode geometries and various discharge types for water treatment, of which the applications have been employed industrially on different scales. The reactive species such as OH radicals, O3, H2O2 and HO2 can be generated from the reactions that occur at the plasma-water interface. For discharges above water, the effect of positive gas ions, which lead to the formation of positive water ions, is considered the main pathway for OH radical formation; while for the discharge under water, the water dissociation by electron collisions is considered as the main pathway.;However, the reaction zone for the production of reactive species (gas or liquid phase) is still controversial. This thesis presents a study of the plasma generated in the gas phase in contact with water by various discharge types for water treatment. The discharge characteristics, OH radical and H2O2 production, and solution conductivity and pH variation were investigated and compared under different experimental conditions. The degradation of methylene blue dye was investigated under DBD.;The transition of impulsive current discharges into impulsive-diffuse discharges was recorded by increasing the solution conductivity; a further transition of the discharge type into a spark was recorded when the solution conductivity was increased to >2.4 mS/cm. The H2O2 energy efficiency of 1.1 g/kWh was recorded under positive impulsive current discharges in N2 and helium.;The highest charge/H2O2 ratio of 1:1.26 was recorded under positive impulsive current discharges in O2 and N2. Under positive DC glow discharges, the H2O2 energy efficiency of 1.9 g/kWh was recorded in air discharges, and was slightly increased to 1.95 g/kWh when using a flow liquid electrode. Increased solution acidity and basicity from neutral solution have negative effects on H2O2 production. A significant amount of water vapour was observed under DC glow discharges, resulting in a negative effect on H2O2 production.;Under negative discharges, no H2O2 production was detected in water after O2, N2, air and helium discharge treatments. In DBD, a threshold voltage is required to initiate electrical discharges between the glass plate and the water, through the micro-pores. The H2O2 production yield of 1.1 g/kWh was recorded in O2 discharge treatment. The degradation yield of methylene blue dye of 310 g/kWh was achieved within the first minute of O2 discharge treatment.Plasma generated in contact with water has been extensively investigated in various electrode geometries and various discharge types for water treatment, of which the applications have been employed industrially on different scales. The reactive species such as OH radicals, O3, H2O2 and HO2 can be generated from the reactions that occur at the plasma-water interface. For discharges above water, the effect of positive gas ions, which lead to the formation of positive water ions, is considered the main pathway for OH radical formation; while for the discharge under water, the water dissociation by electron collisions is considered as the main pathway.;However, the reaction zone for the production of reactive species (gas or liquid phase) is still controversial. This thesis presents a study of the plasma generated in the gas phase in contact with water by various discharge types for water treatment. The discharge characteristics, OH radical and H2O2 production, and solution conductivity and pH variation were investigated and compared under different experimental conditions. The degradation of methylene blue dye was investigated under DBD.;The transition of impulsive current discharges into impulsive-diffuse discharges was recorded by increasing the solution conductivity; a further transition of the discharge type into a spark was recorded when the solution conductivity was increased to >2.4 mS/cm. The H2O2 energy efficiency of 1.1 g/kWh was recorded under positive impulsive current discharges in N2 and helium.;The highest charge/H2O2 ratio of 1:1.26 was recorded under positive impulsive current discharges in O2 and N2. Under positive DC glow discharges, the H2O2 energy efficiency of 1.9 g/kWh was recorded in air discharges, and was slightly increased to 1.95 g/kWh when using a flow liquid electrode. Increased solution acidity and basicity from neutral solution have negative effects on H2O2 production. A significant amount of water vapour was observed under DC glow discharges, resulting in a negative effect on H2O2 production.;Under negative discharges, no H2O2 production was detected in water after O2, N2, air and helium discharge treatments. In DBD, a threshold voltage is required to initiate electrical discharges between the glass plate and the water, through the micro-pores. The H2O2 production yield of 1.1 g/kWh was recorded in O2 discharge treatment. The degradation yield of methylene blue dye of 310 g/kWh was achieved within the first minute of O2 discharge treatment
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