The investigation of failure in brittle materials, subjected to dynamic transient loading conditions, represents one of the ongoing challenges in the mechanics community. Progresses on this front are required to support the design of engineering components which are employed in applications involving extreme operational regimes. To this purpose, this thesis is devoted to the development of a framework which provides the capabilities to model how crack patterns form and evolve in brittle materials and how they affect the quantitative description of failure. The proposed model is developed within the context of diffusive interfaces which are at the basis of a new class of theories named phase field models. In this work, a set of additional features is proposed to expand their domain of applicability to the modelling of (i) rate and (ii) pressure dependent effects. The path towards the achievement of the first goal has been traced on the desire to account for micro-inertia effects associated with high rates of loading. Pressure dependency has been addressed by postulating a mode-of-failure transition law whose scaling depends upon the local material triaxiality. The governing equations have been derived within a thermodynamically-consistent framework supplemented by the employment of a micro-forces balance approach. The numerical implementation has been carried out within an updated lagrangian finite element scheme with explicit time integration. A series of benchmarks will be provided to appraise the model capabilities in predicting rate-pressure-dependent crack initiation and propagation. Results will be compared against experimental evidences which closely resemble the boundary value problems examined in this work. Concurrently, the design and optimization of a complimentary, improved, experimental characterization platform, based on the split Hopkinson pressure bar, will be presented as a mean for further validation and calibration.

This research focuses on the relationship between self-esteem, graduateness skills and attributes and career adaptability among young adults in the school-to-work transition phase to assist them in dealing with the transitions they are faced with during the school-to-work transition phase in the hopes of making them more career adaptable and employable. A cross-sectional quantitative research approach was followed, and a non-probability convenience sample (N = 332) of undergraduate black (98.5%) and female (62%) young emerging adults (18 to 29 years) at a Further Education and Training (FET) college in South Africa participated in the study. A canonical correlation analysis indicated a significant overall relationship between the graduateness/self-esteem canonical variate and the career adaptability canonical variate. Hierarchical regression analyses indicated that the relationship between graduateness skills and attributes and career adaptability was moderated by self-esteem. Tests for mean differences revealed that males and females differed significantly regarding their personal self-esteem and lie items. Recommendations are suggested for use by human resource professionals in terms of career development practices. / Human Resource Management / M. Com. (Human Resource Management)

The thesis deals with a problem of the design of information system. The design of system is provided with Rational Unifeid Process methodology. This thesis creates a list of requests to system. It makes an analysis and a design of current information system. It useses a RUP methodology to realize two first phases, inception phase and elaboration phase. Created elaboration phase of document is a base for creating programming prototype in Ruby on Rails environment using Ruby language with combination of HTML code.