Effects of microstructure on long and short crack growth in nickel base superalloys

The use of engineering materials in critical applications necessitates the accurate prediction of component lifetime for inspection and renewal purposes. In fatigue limited situations, it is necessary to be able to predict the growth rates of cracks from initiation at a defect through to final fracture. To this end, fatigue crack growth data are presented for different microstructures of typical nickel base superalloys used in gas turbine engines. Crack growth behaviour throughout the life history of the crack, i.e. from the short crack through to the long crack propagation regime, is described for each microstructural condition and discussed in terms of current theories of fatigue crack propagation.

On the compatibility of benevolence and self-interest:philanthropy and entrepreneurial orientation

This article explores the philanthropy of owner–managers of small- and medium-sized enterprises (SMEs) investigating whether and why more entrepreneurially oriented SMEs are also more likely to engage in philanthropic activities. We find support for a positive link between entrepreneurial orientation (EO) and philanthropy in a representative sample of 270 Lithuanian SMEs controlling for alternative explanations. We highlight that philanthropy is relatively common among SME owner–managers and thus complement existing research which views philanthropy as sequentially following wealth generation. In line with our theorizing, further qualitative findings point to drivers of philanthropy beyond those considered in the dominant strategic-instrumental perspective. Building on social-psychological theories of motivation, we argue and confirm that philanthropy can also be an expression of owner–managers’ altruistic values; these values can be compatible and even mutually reinforcing with entrepreneurship. Our study is set in a transition economy, Lithuania, facilitating the analysis of heterogeneity in attitudes toward philanthropy.

A mixed methods investigation of parental factors in non-attendance at general paediatric hospital outpatient appointments

Non-attendance at paediatric outpatient appointments results in delayed diagnosis and treatment, putting children at risk of avoidable ill health, and incurring considerable health service costs. Links between missed appointments and clinical, socio-demographic, and access-related factors have been indicated, but parental cognitions associated with non-attendance have yet to be investigated. The aims of this project were to evaluate the effectiveness and theoretical bases of existing interventions designed to reduce non-attendance; to consider the ways in which missed appointments are managed by healthcare providers; to explore parents’ beliefs and experiences of attending and missing appointments; and to investigate the factors underlying these beliefs. A systematic literature review focusing on non-attendance interventions was conducted Within a mixed methods framework, interviews were conducted with healthcare professionals, subsequent interviews were conducted with parents who had attended or missed a General Paediatric outpatient appointment, and a cross-sectional questionnaire study of parents’ beliefs was implemented. The systematic review revealed that text message appointment reminders are effective at reducing non-attendance rates, but that no interventions have thus far been developed using theories of behaviour. Healthcare professionals recognised both barriers and parents’ beliefs as influences on attendance, but also believed there were ‘types’ of families who miss appointments. Healthcare professionals disagreed somewhat about how non-attendance should best be managed. The parent interview study found six themes. The findings reflect parents’ perceptions about the importance of attending and of their ability to attend. The results of the questionnaire study corroborate this structure of beliefs as the analysis produced two factors, the perceived ‘worth’ of attending and anticipated ‘worry’ when attending. This thesis demonstrates an original approach to investigating non-attendance at children’s outpatient appointments, using mixed methods and adopting a psychological rather than service-use perspective. The findings contribute to Health Psychology theory and offer recommendations for healthcare providers.

An examination of the determinants of entrepreneurship at the regional level:the case of East Midlands region

Despite the importance of new firms to the economy, determinants of start-ups have mainly been examined at a country level and discussion of regional entrepreneurial activity has received less attention. Since there are significant variations in entrepreneurship rates across and within countries, such an investigation at a regional level would help in gaining an in depth understanding of the impact of the individual level resource endowments and neighbourhood characteristics on an individual’s decision to engage in entrepreneurial activity. The main aim of the thesis is to explore various theories of entrepreneurship and develop integrated frameworks for examining the determinants of entrepreneurial activity at a neighbourhood level in the East Midlands region in England. The specific objectives of the thesis are to examine how the individual level resources and the neighbourhood characteristics: (i) combine to influence an individual to engage in the different stages of the entrepreneurial process, (ii) influence natives and migrants to engage in start up activity and (iii) influence women and men to become self-employed and ambitious entrepreneurs. In terms of the methodology, the empirical analysis is based on two databases combined: 2006 to 2009 GEM East Midlands region and the English Index of Multiple Deprivation dataset. Based on the critical review of the literature on entrepreneurship the thesis develop theoretical frameworks which led to formulate hypotheses related to the differentiated impact of both individual and neighbourhood level factors on the propensity of an individual to be involved in entrepreneurial activity. The findings indicate that the determinants of entrepreneurial activity vary with human, financial and the local environment factors affecting the entrepreneurial process. Finally, the thesis calls for caution when developing and applying generic and specific policy measures aimed at promoting entry into entrepreneurship.

Assuming identities online:experimental linguistics applied to the policing of online paedophile activity

This article uses a research project into the online conversations of sex offenders and the children they abuse to further the arguments for the acceptability of experimental work as a research tool for linguists. The research reported here contributes to the growing body of work within linguistics that has found experimental methods to be useful in answering questions about representation and constraints on linguistic expression (Hemforth 2013). The wider project examines online identity assumption in online paedophile activity and the policing of such activity, and involves dealing with the linguistic analysis of highly sensitive sexual grooming transcripts. Within the linguistics portion of the project, we examine theories of idiolect and identity through analysis of the ‘talk’ of perpetrators of online sexual abuse, and of the undercover officers that must assume alternative identities in order to investigate such crimes. The essential linguistic question in this article is methodological and concerns the applicability of experimental work to exploration of online identity and identity disguise. Although we touch on empirical questions, such as the sufficiency of linguistic description that will enable convincing identity disguise, we do not explore the experimental results in detail. In spite of the preference within a range of discourse analytical paradigms for ‘naturally occurring’ data, we argue that not only does the term prove conceptually problematic, but in certain contexts, and particularly in the applied forensic context described, a rejection of experimentally elicited data would limit the possible types and extent of analyses. Thus, it would restrict the contribution that academic linguistics can make in addressing a serious social problem.

The role of wisdom in organisational leadership

This thesis begins with a review of the literature on wisdom models, theories of wise leadership, and existing wisdom measures. It continues with a review of how the concept of wisdom may add value to existing leadership models, highlighting the need to empirically identify the characteristics of wise leaders and develop a wise leadership measure. A nomological framework for wise leadership is then presented. Based on a review of the wisdom and leadership paradigms, a mixed-methods research design is described for three studies to define the characteristics of wise leadership in organisations; identify specific leadership challenges that might require wise responses; and to develop the wise leadership measure comprising of vignettes. The first study involves critical incident interviews with 26 nominated wise leaders and 23 of their nominators, which led to the identification of nine wise leadership dimensions which include Strong Ethical Code, Strong Judgement, Optimising Positive Outcomes, Managing Uncertainty, Strong Legacy, Leading with Purpose, Humanity, Humility, and Self-Awareness. The second study includes critical incident interviews with 20 leaders about organisational challenges associated with the nine dimensions, to elucidate the wise leadership measure. The third study includes the design of 45 vignettes based on organisational challenges that measure the nine wise leadership dimensions. The measure is then administered to 250 organisational leaders to establish its construct validity, leading to the selection of 18 vignettes forming the final wise leadership measure. Theoretical, methodological and practical implications of this research are then discussed with recommendations for future research.

Degree of vertical integration and its buffering effects on political uncertainty

The focus of this study is on the governance decisions in a concurrent channels context, in the case of uncertainty. The study examines how a firm chooses to deploy its sales force in times of uncertainty, and the subsequent performance outcome of those deployment choices. The theoretical framework is based on multiple theories of governance, including transaction cost analysis (TCA), agency theory, and institutional economics. Three uncertainty variables are investigated in this study. The first two are demand and competitive uncertainty which are considered to be industry-level market uncertainty forms. The third uncertainty, political uncertainty, is chosen as it is an important dimension of institutional environments, capturing non-economic circumstances such as regulations and political systemic issues. The study employs longitudinal secondary data from a Thai hotel chain, comprising monthly observations from January 2007 – December 2012. This hotel chain has its operations in 4 countries, Thailand, the Philippines, United Arab Emirates – Dubai, and Egypt, all of which experienced substantial demand, competitive, and political uncertainty during the study period. This makes them ideal contexts for this study. Two econometric models, both deploying Newey-West estimations, are employed to test 13 hypotheses. The first model considers the relationship between uncertainty and governance. The second model is a version of Newey-West, using an Instrumental Variables (IV) estimator and a Two-Stage Least Squares model (2SLS), to test the direct effect of uncertainty on performance and the moderating effect of governance on the relationship between uncertainty and performance. The observed relationship between uncertainty and governance observed follows a core prediction of TCA; that vertical integration is the preferred choice of governance when uncertainty rises. As for the subsequent performance outcomes, the results corroborate that uncertainty has a negative effect on performance. Importantly, the findings show that becoming more vertically integrated cannot help moderate the effect of demand and competitive uncertainty, but can significantly moderate the effect of political uncertainty. These findings have significant theoretical and practical implications, and extend our knowledge of the impact on uncertainty significantly, as well as bringing an institutional perspective to TCA. Further, they offer managers novel insight into the nature of different types of uncertainty, their impact on performance, and how channel decisions can mitigate these impacts.

Exact solution for the energy spectrum of Kelvin-wave turbulence in superfluids

We study the statistical and dynamical behavior of turbulent Kelvin waves propagating on quantized vortices in superfluids and address the controversy concerning the energy spectrum that is associated with these excitations. Finding the correct energy spectrum is important because Kelvin waves play a major role in the dissipation of energy in superfluid turbulence at near-zero temperatures. In this paper, we show analytically that the solution proposed by [L’vov and Nazarenko, JETP Lett. 91, 428 (2010)] enjoys existence, uniqueness, and regularity of the prefactor. Furthermore, we present numerical results of the dynamical equation that describes to leading order the nonlocal regime of the Kelvin-wave dynamics. We compare our findings with the analytical results from the proposed local and nonlocal theories for Kelvin-wave dynamics and show an agreement with the nonlocal predictions. Accordingly, the spectrum proposed by L’vov and Nazarenko should be used in future theories of quantum turbulence. Finally, for weaker wave forcing we observe an intermittent behavior of the wave spectrum with a fluctuating dissipative scale, which we interpreted as a finite-size effect characteristic of mesoscopic wave turbulence.

Detecting expressions of blame or praise in text

The growth of social networking platforms has drawn a lot of attentions to the need for social computing. Social computing utilises human insights for computational tasks as well as design of systems that support social behaviours and interactions. One of the key aspects of social computing is the ability to attribute responsibility such as blame or praise to social events. This ability helps an intelligent entity account and understand other intelligent entities’ social behaviours, and enriches both the social functionalities and cognitive aspects of intelligent agents. In this paper, we present an approach with a model for blame and praise detection in text. We build our model based on various theories of blame and include in our model features used by humans determining judgment such as moral agent causality, foreknowledge, intentionality and coercion. An annotated corpus has been created for the task of blame and praise detection from text. The experimental results show that while our model gives similar results compared to supervised classifiers on classifying text as blame, praise or others, it outperforms supervised classifiers on more finer-grained classification of determining the direction of blame and praise, i.e., self-blame, blame-others, self-praise or praise-others, despite not using labelled training data.

Mixing theory for culture and harvest in bioreactors of human mesenchymal stem cells on microcarriers

The use of human mesenchymal stem cells (hMSCs) in regenerative medicine is a potential major advance for the treatment of many medical conditions, especially with the use of allogeneic therapies where the cells from a single donor can be used to treat ailments in many patients. Such cells must be grown attached to surfaces and for large scale production, it is shown that stirred bioreactors containing ~200 μm particles (microcarriers) can provide such a surface. It is also shown that the just suspended condition, agitator speed NJS, provides a satisfactory condition for cell growth by minimizing the specific energy dissipation rate, εT, in the bioreactor whilst still meeting the oxygen demand of the cells. For the cells to be used for therapeutic purposes, they must be detached from the microcarriers before being cryopreserved. A strategy based on a short period (~7 min) of very high εT, based on theories of secondary nucleation, is effective at removing >99% cells. Once removed, the cells are smaller than the Kolmogorov scale of turbulence and hence not damaged. This approach is shown to be successful for culture and detachment in 4 types of stirred bioreactors from 15 mL to 5 L.