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Additive Manufacturing (AM), the fabrication of 3-D parts from CAD models, is a disruptive technology that is transforming the manufacturing industry. In any manufacturing process, understanding the process-structure-property-performance (PSPP) linkage is crucial to predict the lifespan of the manufactured component. In the PSPP linkage, the solidification microstructure (liquid-solid phase transformation) is one of the important factors affecting the mechanical property and performance of the additively manufactured components. During rapid solidification, the solidification microstructure is dictated by the thermal gradient (G) at the liquid-solid interface and velocity (R) of the liquid-solid interface. In this work, the transient heat transfer and fluid flow within the molten pool is numerically analyzed using Truchas, a solidification code developed at Los Alamos National Laboratory. The spatial and temporal variations of temperature gradient (G) and growth velocity (R) at the liquid-solid interface of the melt pool were calculated using the data from numerical modeling.1. The obtained transient knowledge from numerical modeling is used to design new melt scan strategies for an electron beam powder bed AM system (Arcam®) and achieve the following.- Control the grain size of the columnar grains.- Control the grain morphology transition (Columnar to Equiaxed).2. The effect of build geometry on the grain morphology control has been reported. It is found that the scan parameters have to be modified as a function of geometry. The data from in-situ process monitoring (infrared imaging) is also analyzed to distinguish the underlying grain morphology.3. The effect of fluid flow and surface tension as a function of different surfactant concentration is analyzed numerically and compared with pure heat conduction simulations. It is concluded that the necessity of fluid flow in the model depends on the scan strategy in addition to the alloy dependent surface tension.

This thesis explores the individual engagement experience at work, what influences this experience and how employees at different career stages experience engagement. This research draws on theories of personal engagement, career stages and structured antagonism. The aim is to expand our understanding of how engagement is experienced and influenced in order to build a conceptual model of the individual engagement experience. The research comprises an indepth case study within a Dutch hospital consisting of thirty in-depth interviews with nurses, supported by four weeks of observations, and an analysis of organisational documents. Based on the findings, a conceptual model was developed capturing the complexity of engagement and acknowledging its fluctuating and contextual nature. The research shows that the individual engagement experience consists of three layers: job; departmental, and organisational engagement. These three layers are influenced by four different resources and hindrances: task; personal; relational, and organisational. This model is applied to four different career stages: exploratory; early advancement, late advancement, and maintenance career stage. The application of the model to the different career stages indicates that individuals within different career stages experience engagement differently, influenced by different resources and hindrances. For employees in the early career stages, the engagement experience is affected by job related influences as well as career progression and self-development. Whereas in the later career stages, mentoring as well as outside work life influences affect the engagement experience. I incorporate structured antagonism theory which recognises unequal power relationships and unaligned interests between employee and employer. In incorporating this stance, I discuss how power influences the employee's engagement experience. Within the engagement experience, I identify how employees have the need to receive engagement from the management of their organisation, in a way that makes the employees feel incorporated, valued and seen. If this engagement is not reciprocated, this can result in a negative effect on the engagement experience as well as different hindrances such as increased work pressure or intensified hindrances relating to organisational processes.

The study of engagement concepts is intended to enhance our understanding of its nature and solve engagement enactment problem in organisations. Key proponents suggest that benefits from engaging accrue to both individuals and organisations (Kahn, 1990; Schaufeli, Salanova, Gonzalez_Roma and Bakker, 2002). And yet, little research has looked at the individuals’ perspectives. As Shuck (2011) highlighted, the preference of individuals needs to be uncovered before it can be acted upon. However, a separation of the two prominent theoretical perspectives used to describe and explain its dynamics has always been an important preference in the literature. From an opposite direction, Sonnentag’s (2011) suggestion for the integration of the work engagement and the personal engagement concepts raises the question of a method for orientating this integration. Hence, gaps exist as to how an acceptable multiple perspectives driven model can be established. To bridge these gaps, this study followed suggestions by Whetten (2009) to develop a combined personal-work engagement concept, empirically tested this consolidated framework and examined the perspectives of 24 self-employed and employed Nigerians. The findings provide evidence on some aspects of the successful application of the combined personal-work engagement framework. The conclusions reached assert that at the individual level, engagement patterns occurring among the individuals’ reasoning reflects an underlying dimension: a distinction made between the regard and disregard for hindering factors that seems to affect the engagement level. At higher levels of engagement, individuals regard helping factors and disregard hindering factors and this pattern seemed to have a degree of support that is not found at lower levels. At lower levels individuals regard helpful factors and regard hindering factors. A limitation is that the findings only offers guarantees that more often than not, the relationship is an expression of engaging, more work needs to be done to follow-on from this study.

This submission provides more than 25 years of historical context to the concept of reward strategy and its evolution in the UK context, isolating and describing my own part in it, supported by my 16 publications referenced on this subject. As well as researching and re-conceptualising ideas of reward strategy and their importance in the UK context, three other key dimensions which my research has highlighted, have been about: focusing more on reward strategy application and securing line manager and employee engagement; the importance of researching and assessing the effectiveness of reward policies and how this can be done; and the need to adopt an organisation-specific, total rewards perspective on reward strategy. I have adapted the concept and my research in response to economic, social and political developments over that period and, uniquely, integrated academic and practitioner perspectives on this area to promote both the creation and application of new knowledge and evidence-based practice. As I have worked on the cusp of academic enquiry and professional practice, a PhD by Publication is a particularly relevant format in which to submit my work. I have in the process created new knowledge at the forefront of the discipline, for example in redefining the concepts of reward strategy and total rewards in an innovative and more effective manner; demonstrated the acquisition and understanding of knowledge in the field, for example in summarising and relating research literature in the formerly relatively distinct areas of reward management and employee engagement; conceptualised and run major research projects, for example investigating reward effectiveness; and displayed a full range of research methods in my work, including quantitative, qualitative, cross-sectional and longitudinal studies. Collectively, my work through the publications listed has offered a detailed exploration of the concept and application of reward strategy in the UK context, bringing together academic and practitioner perspectives and informed by and influencing leading academics and practitioners in the field. This sustained and coherent body of work makes a significant and original contribution to the present state of knowledge on reward thinking and practice and in related HR and management areas.

Using data from the British Household Panel Survey, the thesis provides both empirical evidence and theoretical explanations to show the nature, behaviour, and roles of job satisfaction and personality on self-employed entrepreneurship survival. The thesis poses three research questions: Does self-employed job satisfaction adapt? Does job satisfaction predict the likelihood of survival of self-employed businesses after start-ups? Does personality play a role in the survival probability of men and women who manage self-employed enterprises? The first question hypothesises that the initial boost in job satisfaction associated with the transition into self-employment is transitory, dissipating rapidly during the early years of the self-employment venture. Findings suggest that men who become self-employed enjoy a more permanent boost in overall job satisfaction, satisfaction with pay and, to some extent, satisfaction with the nature of the work itself. Women experience a boost in satisfaction with the nature of the work itself and to, a lesser extent, a boost in satisfaction with pay. Both of these effects for women are short-lived, casting doubt on the importance of job satisfaction, work-schedule flexibility, and work-life balance as pull factors into self-employment. The second question re-examines the link between job satisfaction and self-employment survival and argues that the relationship is not necessarily a contemporaneous one. That is, job satisfaction at time t is not necessarily the best predictor of survival/exit at time t, but it is the whole self-employment experience that matters rather than the last reported satisfaction. The results show that job satisfaction does not predict the probability of survival. Rather, the maximum job satisfaction and the peak-end combinations during the self-employment episode are better predictors of survival. The last question draws on the robust measures of personality to forecast the survival chances of men and women-managed enterprises, paying attention to occupational differences. Findings show that, unlike previous studies, different personality traits predict men and women-managed ventures survival chances over time; and that the likelihood of survival overtime of both men and women-managed enterprises by occupational categories is dependent on the different personality traits complementing themselves in different scenarios. The thesis contributes to the existing literature by offering a novel behavioural research perspective into the analysis of self-employment dynamics.