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This thesis attempts to investigate the signalling role of managerial tone in the context of corporate disclosure. It first starts with a literature review in-depth to review how managers use their tone (roles) and why they use them(determinants). A detailed analysis of 81 published studies between 2010 and 2021 informs scholars about the current state of research on managerial tone. Based on a signalling framework, this thesis examines the following questions: Does managerial tone have a signalling role? Does the signal (tone) match the latent information it intends to convey? Can the receiver(analysts) correctly interpret the signal and send feedback to confirm(disconfirm) the signal? Does the signalling environment impact signalling effectiveness? How does tone signalling effectiveness varies across signaller's characteristics? Using a sample of earnings conference call transcripts from FTSE350 firms, empirical tests in this thesis provide evidence that managerial tone can produce effective signals matching the private information from managers. Analysts accurately understand tone signals and send confirmation feedback to managers. The information environment can moderate signalling effectiveness. Beyond this, top managers with a stronger ability and signalling willingness can strengthen tone signalling effectiveness, while top managers with less signalling willingness weaken tone signalling effectiveness. The findings suggest that managerial tone represents a reliable signalling device for transmitting latent information about a firm's quality and future performance and that receivers can correctly understand this signal and develop a consistent interpretation. It implies that managerial tone can be used for two-way communication. Further, prestigious top managers with more ability and signalling willingness are more valuable for firms to improve their signalling process.

After nearly two decades of market-related changes since the introduction of the 1990 NHS and Community Care Act, most of the local government authorities in England and Wales are using high levels of commissioning (outsourcing) from the independent sector in the provision of social care for the elderly. However, it is identified that there are significant differences in their performance in delivering outcomes and capacity to improve services, even when they use the same level of outsourcing. To understand the issues behind these differences, this thesis investigates the relationship between the local authorities and their social care providers from the perspective of contract management and communication channels, as they are two critical aspects of managing outsourcing relationships. As an innovative approach in the provision of social care services, the Direct Payments scheme represents a move from traditional service delivery controlled by the local authority to user-controlled services. This shift is complex and time consuming, and needs some supporting work to be undertaken in advance to meet the challenges. Local authorities need to define a new strategic commissioning role and develop new skills in order to cope with changes in the social care market under Direct Payments. Detailed analysis of the challenges for local authorities and how to promote Direct Payments is performed in this thesis. Facing current issues and future challenges, e-business solutions can be exploited to improve the provision of social care services. For example, e-procurement systems and technologies help to improve the efficiency of information flows, and to meet the increasing demands for customized, responsive and diversified services. A framework for public procurement of social care services is constructed here based on the application of advanced information technologies. In China, as the largest developing country, the traditional family-based system cannot meet the increasing demands of care services for the elderly. Within this context, the Chinese government is planning to explore the feasibility of new development strategies to encourage private investors and corporations to operate in the elderly care market. This thesis studies the valuable experience gained from reforms in social care markets in England and Wales to learn lessons that might help in the development of the social care market for the elderly in China. Interviews are conducted in local government authorities in both England and China including the social services departments of the five Merseyside authorities and the Qingdao Civil Affairs Bureau in China. Complementary evidence is taken from interviews with 4 independent providers in England, and 5 independent providers and 2 in-house providers in Qingdao. Evidence is also taken from the literature including government reports from the UK and China, and a previous study of commissioning care in Wales.

H2S localized corrosion, occurring at discrete sites on a steel surface, can result in fast penetration of pipeline walls and loss of containment. This mode of metal attack is generally considered to be the main cause for catastrophic corrosion failures of facilities in the oil and gas industry. Hence, the prediction and control of H2S localized corrosion is a significant challenge for assuring asset integrity in oil and gas fields containing H2S. The purpose of this dissertation project is to explore, heretofore poorly understood, localized corrosion mechanisms related to the formation of iron sulfide polymorphs and related phases.In order to make this investigation possible, a thermodynamic model was initially developed as a tool to determine experimental conditions that could potentially replicate localized corrosion associated with iron sulfide polymorphism in an aqueous H2S system. Equilibrium expressions for H2S solubility and dissociation constants were reviewed and compared. Models to predict water chemistry of an H2S-H2O system were built and verified against experimental measurements. In order to predict the formation and dissolution of iron sulfides, their solubility limits were experimentally measured in an H2S-H2O-Fe2+ system. At 25oC, the measured pKsp,2 values were observed to change with time as the identity of the observed iron sulfide type changed. The pKsp,2 of mackinawite at 25oC was measured as 3.6 ± 0.2. Pyrite and greigite were observed at 60oC. Greigite was dominant around pH 5 with a pKsp,2 9.8 ± 0.5, while pyrite was dominant around pH 3.5 with pKsp,2 6.5 ± 0.5.The electrochemical thermodynamics of an H2S-H2O-Fe system were then investigated, with iron sulfides selected in relation to the oil and gas industry. Mackinawite, pyrrhotite, greigite, and pyrite were taken into consideration for Pourbaix diagram generation, accompanied by a complete accounting of all the assumptions, underlying thermodynamic data, and reaction mechanisms. Generated Pourbaix diagrams were validated by long-term experiments at different temperatures (25oC and 80oC) and by adjusting solution pH. Following the establishment of the thermodynamic model, experimental conditions leading to the formation of different iron sulfides as corrosion products in a sour environment were established. A strong correlation between the formation of greigite and/or pyrite on a steel surface and onset of localized corrosion was observed. Localized corrosion was absent when neither greigite nor pyrite formed. Consequently, the formation of greigite and/or pyrite was hypothesized to play an important role in the initiation of localized corrosion. Novel experiments involving deposition of pyrite on the steel surface were then designed and conducted. It was found that the galvanic coupling between pyrite particles and steel is the dominant mechanism for this type of localized corrosion.Finally, a descriptive model was built to answer when, where, and how this type of localized corrosion occurs in a sour environment. This model can provide guidance for the mitigation of localized corrosion in field conditions.

This dissertation studies the deformation behavior of high temperature alloys with an aim to understand creep damage and fracture mechanics of these materials. First, we study the creep fatigue deformation of a unified viscoplastic material subjected to uniaxial cyclic loading using a dynamical system approach. We find oscillation of back stress significantly increases the inelastic strain accumulation in a cyclic test. The accumulated inelastic strain at long times are sensitive to the initial condition (e.g. whether one starts with tension or compression). We define a ratcheting ratio to quantify the interaction of creep and cyclic plasticity on the accumulated inelastic strain per cycle. The second part of the dissertation focuses on solving the asymptotic stress and strain field near the tip of a plane strain Mode I stationary crack in a viscoplastic material. For small scale creep where the region of inelasticity is small in comparison with typical specimen dimensions, our asymptotic and finite element analysis show that the near tip stress field has the same singularity as elastic power law creeping materials with a time dependent amplitude. This amplitude is found to vanish at long times and the elastic K field dominates. For the case of cyclic loading, we study the effect of stress ratio on inelastic strain and find that the strain accumulated per cycle decreases with stress ratio. iii The third part of the dissertation carries out finite element simulations on the planar deformation of random sized power law creeping grains with sliding and cavitating boundaries. Grain boundary sliding and grain boundary separation due to cavity nucleation and growth are incorporated into a cohesive zone model. Finite element simulation of a relaxation test shows that more grain boundary separation occurs in a microstructure with sliding resistant grain boundaries than in a microstructure with more freely sliding grain boundaries. The overall inelastic strain rate of the microstructure in uniaxial tension test is found to be greatly enhanced by grain boundary sliding and grain boundary cavitation. Finally, we extend the cohesive zone model in the third part of the dissertation to account for interface embrittlement caused by grain boundary impurities. Finite element simulation of an uniaxial creep test using a two dimensional random grain structure shows that grain boundary cavitation and interface embrittlement are two competing mechanisms for grain boundary separation. The occurrence of one grain boundary separation mode would slow down or even inhibit the other. iv

Tocols are naturally occurring vitamin E isomers. Corn is one of the rich sources of tocopherols and tocotrienols. Currently, corn is mostly processed by wet-milling. The first critical step of corn wet-milling is steeping---the soaking of the corn in water under controlled conditions of time, temperature and SO2 concentration. It was reported that only 27% of total tocols was recovered after wet-milling process. However, it was not clear which processing steps were detrimental to the tocols. The objective of this study is to develop a method for HPLC analysis of tocols in steeped corn and to study the effect of processing conditions on retention of different isomers. In this investigation, the extractions with saponification and without saponification were compared. The results indicated that steeped corn samples must be saponified with ethanolic KOH prior to determination of tocols. The optimal conditions for saponification were found to be 70 degrees for 15 minutes. The steeping conditions have different effects on retention of individual isomers.