New methods for controlling twin configurations and characterizing twin boundaries in 5M Ni-Mn-Ga for the development of applications

Traditional methods for studying the magnetic shape memory (MSM) alloys Ni-Mn-Ga include subjecting the entire sample to a uniform magnetic field or completely actuating the sample mechanically. These methods have produced significant results in characterizing the MSM effect, the properties of Ni-Mn-Ga and have pioneered the development of applications from this material. Twin boundaries and their configuration within a Ni-Mn-Ga sample are a key component in the magnetic shape memory effect. Applications that are developed require an understanding of twin boundary characteristics and, more importantly, the ability to predictably control them. Twins have such a critical role that the twinning stress of a Ni-Mn-Ga crystal is the defining characteristic that indicates its quality and significant research has been conducted to minimize this property. This dissertation reports a decrease in the twinning stress, predictably controlling the twin configuration and characterizing the dynamics of twin boundaries. A reduction of the twinning stress is demonstrated by the discovery of Type II twins within Ni-Mn-Ga which have as little as 10% of the twinning stress of traditional Type I twins. Furthermore, new methods of actuating a Ni-Mn-Ga element using localized unidirectional or bidirectional magnetic fields were developed that can predictably control the twin configuration in a localized area of a Ni-Mn-Ga element. This method of controlling the local twin configuration was used in the characterization of twin boundary dynamics. Using a localized magnetic pulse, the velocity and acceleration of a single twin boundary were measured to be 82.5 m/s and 2.9 × 107 m/s2, and the time needed for the twin boundary to nucleate and begin moving was less than 2.8 μs. Using a bidirectional magnetic field from a diametrically magnetized cylindrical magnet, a highly reproducible and controllable local twin configuration was created in a Ni-Mn-Ga element which is the fundamental pumping mechanism in the MSM micropump that has been co-invented and extensively characterized by the author.

How CSR and stakeholder engagement encourage the development of Industrial symbiosis from the management viewpoint?

The thesis aims to understand how CSR and stakeholder engagement can contribute to the development of industrial symbiosis. Theory suggests that corporate social responsibility and stakeholder engagement theories have many similar aspects that correlate with the development of industrial symbiosis. This study is qualitative and empirical suggestions are derived from integrative analysis of literature, secondary data and case study analysis. The empirical findings from the interviews support the framework that is created from the findings of the literature review. The results discovered throughout the thesis research suggest that CSR functions as a theoretical background for industrial symbiosis and stakeholder engagement helps develop more thorough understandings of it from the management viewpoint. Empirical findings and literature review also suggest that in the developing of industrial symbiosis the key aspect are the social characteristics such as a robust management structure, trust between partners and long-term commitment to the common goals that support the development of these symbioses. Also, communication and transparency supports the development of industrial symbiosis. For managerial contribution, this thesis presents organizational practices that can help managers to understand how they can engage in effective engagement with stakeholders in the development of industrial symbiosis.