Abstract Environmental concern and tighter public regulations have created new pressures to reduce effluent loading from kraft pulp bleaching during the past decades. This trend has forced both pulp mills and the related engineering industries to develop and optimise equipment for the pulping processes which fulfils these demands. New pulp washers and washing systems connected with the introduction of new oxygen-based reagents have in particular provided considerably improved tools for reusing process water and thereby essentially reducing effluent discharge or even allowing the implementation of a totally closed water circulation system in kraft pulp bleaching. This study was performed mainly on a laboratory scale at the University of Oulu, but some pilot-scale tests were also performed to confirm the findings of the laboratory-scale evaporation test. Another aim of the pilot-scale tests was to produce enough concentrate for further processing. Conditions were strictly controlled in all the experiments in order to ensure that conclusions could be reached regarding the phenomena examined. The results reported here indicate that the amounts of transition metal ions such as iron, copper or manganese in the process water or water to be recirculated should be kept as low as possible during chlorine dioxide or peracetic acid bleaching, as even a small amount (<<5 ppm) markedly reduced pulp quality and increased reagent consumption. The results also show that evaporation can be used as a method for purifying acidic effluent from both chlorine dioxide and peracetic acid bleaching, and that the resulting condensates were free of transition metals and clean enough for reuse in both bleaching processes. The purity of the condensates was further improved by neutralising the feed pH of the acidic effluents from the bleach plant before evaporation. The results also indicate that the chloride ions in the concentrate arising from evaporation of the acidic effluent from chlorine dioxide bleaching can be removed by a combined acidification/re-evaporation system.

Intelligent systems ought to be distinguished as a special type of systems that require distinctive engineering processes. While this distinction is informally acknowledged by some, practical systems engineering (SE) methodologies for intelligent systems remain primarily rooted in traditional SE paradigms centered around component aggregation. Initially, this dissertation posits that the traditional approach is grounded in the notion of open systems as the fundamental precept, whereas engineering intelligent systems necessitates an alternative approach founded on the principles of closed systems. This dissertation endeavors to identify potential gaps within the current SE foundations concerning the accommodation of the unique characteristics of intelligent systems, such as continuous learning and sensitivity to environmental changes. Furthermore, it argues for the mitigation of these gaps through the formalization of closed systems precepts. It adopts a systems-theoretic perspective to elucidate the phenomena of closed systems and their intricate interplay with engineering intelligent systems. This research contends that, given the intricate coupling between intelligent systems and their environments, the incorporation of closed systems precepts into SE represents a pivotal pathway to construct engineered intelligence. In pursuit of this objective, this dissertation establishes a formal foundation to delineate closed systems precepts and other fundamental practices. Subsequently, it provides formalism to discern two important categories of closed systems, informationally and functionally closed systems, and their relevance in the domains of engineering and design across diverse levels of system abstraction. Additionally, it explores the practical application of the closed systems precepts through the novel paradigm of core and periphery, followed by its examination within real-world contexts. This dissertation is organizes as follows: Chapter 1 initiates the dissertation by presenting the problem formulation and motivation. It subsequently delves into a thorough literature review and outlines the research's scope and objectives, contributing to the essence of this work. In Chapter 2, a narrative unfolds, elucidating the contributions of the provided papers to the objectives outlined in Chapter 1. This chapter illuminates how each paper aligns with and furthers the overarching goals set forth in the Chapter 1. Chapter 3 serves as a culmination, offering a summary of the accomplishments, acknowledging limitations, and delineating potential avenues for future research within this domain. Paper A is devoted to substantiating the closed notion of intelligence property. In the realm of artificial intelligence (AI), systems are often expected to exert influence upon their environments and, reciprocally, to be influenced by their surroundings. Consequently, a profound interdependence exists between the system and its environment, transcending the confines of conventional input-output relations. In this regard, Paper A postulates that the engineering of intelligent systems mandates an approach that elevates closed systems as foundational precepts for characterizing intelligence as a property contingent upon the system's relationship with its context. The ensuing discussion will juxtapose the viewpoints of open and closed systems, illustrating the limitations of the open system perspective in representing intelligence as a relational property. In response, this paper will advocate for the adoption of the closed system view to establish intelligence as an inherent relational property arising from the system's dynamic interactions with its environment. Paper B is dedicated to the formalization of the closed systems paradigm within SE. In this paper, formalism is proffered for the closed systems precepts, drawing upon systems theory, cybernetics, and information theory. A comprehensive comparison of two closure types, informational and functional closure, within closed systems is presented, underpinned by a common systems-theoretic formal framework. This dissertation contends that by grounding these initiatives in the core and periphery concept, we can facilitate the design and engineering of intelligent systems across multiple levels of abstraction. These levels may span a spectrum from informational closure to a synthesis of informational and functional openness. It posits that this approach represents a versatile, method-agnostic solution to some of the principal challenges encountered when engineering multiple tiers of intelligence for complex systems. Paper C delves into the rise of the concept of core-periphery from some cybernetics principles, such as variety and "The Law of Requisite Variety" and provides a formalism that is a derivation of the mentioned principles in Cybernetics. Later, it elaborates on the practical implications of such concepts in intelligent systems from biological systems and entails an engagement with a CNN model to explore the core and periphery concept within AI-enabled systems. Paper D proposes the practical implementation of the closed systems doctrine in SE, offering frameworks that rigorously define the boundaries between closed systems and their environment. These frameworks are meticulously designed to account for stakeholder requirements and the inherent design constraints of the system. This paper illustrates practical applications of informational and functional closure within SE processes, leveraging a hypothetical example for elucidation. It focuses on two aspects of engineering intelligence, scope and scale to provide a platform for the utilization of closed systems precepts. / Doctor of Philosophy / There has been a longstanding call within the Systems Engineering (SE) community for the development of a comprehensive SE theory. This endeavor seeks to bestow upon the field of SE the requisite credibility to stand autonomously as an engineering discipline, capable of addressing the contemporary engineering challenges that confront us. In the pursuit of establishing SE as a distinct engineering field, it becomes imperative to furnish precise and formal definitions for the fundamental concepts that underpin SE processes. Presently, the absence of concrete formalism and clear distinctions surrounding certain core concepts introduces ambiguity into various SE practices. Until recently, the immediate necessity for such foundational formalism was not universally acknowledged or appreciated, as engineers predominantly relied on established practices to design traditional engineered systems. These conventional SE practices had withstood the test of time, until the emergence of a new generation of complex systems characterized by distinctive features. Among these emergent systems, Artificial Intelligent (AI) systems have garnered significant attention, bearing unique attributes that call into question the adequacy of the current SE practices in supporting their development. Consequently, it has been asserted that intelligent systems necessitate the incorporation of new characteristics that render them incompatible with conventional SE practices. This assertion underscores the need for a thorough reevaluation of SE, potentially entailing an expansion of the formalism underpinning its fundamental principles. However, despite these pressing concerns, SE currently lacks a solid theoretical foundation capable of facilitating a paradigm shift away from current practices. The primary objective of this dissertation is to identify the existing gaps responsible for the misalignment between the characteristics of AI systems and prevailing SE practices. Additionally, it seeks to propose innovative methodologies to bridge these gaps effectively. In alignment with this objective, the dissertation provides formalism for these methodologies. Finally, this dissertation aims to provide practical implication of such formalism to validate their applicability. In summary, the central research question, along with the ensuing objectives of this dissertation, can be articulated as follows: What aspects of SE are insufficient for engineering the new characteristics demanded by intelligent systems? What specific actions need to be undertaken to rectify the gaps within SE for intelligent systems? What theoretical foundation and formalism are essential to address these deficiencies within the SE process? What are the practical implications of these efforts for SE processes, as exemplified by real-world scenarios?

This study is geared at an open systmes critique of the macro theories of development. It is highlighted in this study that we are living through the realities of the open systems, and yet much of development thought is based on closed systems philosophies, principle and ideologies. The first chapter gives an orientation into the origins of both the closed systems and open systems paradigms respectively. Included in this orientation chapter, is the literature review of the various research contributions of the major trends in development thought. The second chapter expands on the evolution of the closed systems paradigm and its influences on development thought. This chapter further explains the attendant philosophies, principles and ideologies that underlie the closed systems paradigm. The third chapter captures the open systems paradigm and its influences on contemporary development discourse. Further to the discussion on the closed systems paradigm, the chapter elaborates on the philosophies, principles and processes that underlie this paradigm. The fourth chapter is on a discussion of trends in development thinking, traced from the traditional, through the medieval to the modern, right up to the contemporary. This entails tracing the theory to its ontological background right up to its implications for social reality in contemporary development thought and experience. The fifth chapter is on the open systems critique of the trends in development thinking, while the sixth chapter revisits the open systems paradigm and its implications for development thought. In the seventh chapter is the recapitulation of the findings in the study and recommendations for both development thought and practice. / Development Studies / D.Litt. et Phil. (Development Administration)

This study is geared at an open systems critique of the macro theories of development. It is highlighted in this study that we are living through the realities of the open systems, and yet much of development thought is based on closed systems philosophies, principle and ideologies. The first chapter gives an orientation into the origins of both the closed systems and open systems paradigms respectively. Included in this orientation chapter, is the literature review of the various research contributions of the major trends in development thought. The second chapter expands on the evolution of the closed systems paradigm and its influences on development thought. This chapter further explains the attendant philosophies, principles and ideologies that underlie the closed systems paradigm. The third chapter captures the open systems paradigm and its influences on contemporary development discourse. Further to the discussion on the closed systems paradigm, the chapter elaborates on the philosophies, principles and processes that underlie this paradigm. The fourth chapter is on a discussion of trends in development thinking, traced from the traditional, through the medieval to the modern, right up to the contemporary. This entails tracing the theory to its ontological background right up to its implications for social reality in contemporary development thought and experience. The fifth chapter is on the open systems critique of the trends in development thinking, while the sixth chapter revisits the open systems paradigm and its implications for development thought. In the seventh chapter is the recapitulation of the findings in the study and recommendations for both development thought and practice. / Public Administration and Management / D. Litt. et Phil. (Development Administration)

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This study is geared at an open systmes critique of the macro theories of development. It is highlighted in this study that we are living through the realities of the open systems, and yet much of development thought is based on closed systems philosophies, principle and ideologies. The first chapter gives an orientation into the origins of both the closed systems and open systems paradigms respectively. Included in this orientation chapter, is the literature review of the various research contributions of the major trends in development thought. The second chapter expands on the evolution of the closed systems paradigm and its influences on development thought. This chapter further explains the attendant philosophies, principles and ideologies that underlie the closed systems paradigm. The third chapter captures the open systems paradigm and its influences on contemporary development discourse. Further to the discussion on the closed systems paradigm, the chapter elaborates on the philosophies, principles and processes that underlie this paradigm. The fourth chapter is on a discussion of trends in development thinking, traced from the traditional, through the medieval to the modern, right up to the contemporary. This entails tracing the theory to its ontological background right up to its implications for social reality in contemporary development thought and experience. The fifth chapter is on the open systems critique of the trends in development thinking, while the sixth chapter revisits the open systems paradigm and its implications for development thought. In the seventh chapter is the recapitulation of the findings in the study and recommendations for both development thought and practice. / Development Studies / D.Litt. et Phil. (Development Administration)

This study is geared at an open systems critique of the macro theories of development. It is highlighted in this study that we are living through the realities of the open systems, and yet much of development thought is based on closed systems philosophies, principle and ideologies. The first chapter gives an orientation into the origins of both the closed systems and open systems paradigms respectively. Included in this orientation chapter, is the literature review of the various research contributions of the major trends in development thought. The second chapter expands on the evolution of the closed systems paradigm and its influences on development thought. This chapter further explains the attendant philosophies, principles and ideologies that underlie the closed systems paradigm. The third chapter captures the open systems paradigm and its influences on contemporary development discourse. Further to the discussion on the closed systems paradigm, the chapter elaborates on the philosophies, principles and processes that underlie this paradigm. The fourth chapter is on a discussion of trends in development thinking, traced from the traditional, through the medieval to the modern, right up to the contemporary. This entails tracing the theory to its ontological background right up to its implications for social reality in contemporary development thought and experience. The fifth chapter is on the open systems critique of the trends in development thinking, while the sixth chapter revisits the open systems paradigm and its implications for development thought. In the seventh chapter is the recapitulation of the findings in the study and recommendations for both development thought and practice. / Public Administration and Management / D. Litt. et Phil. (Development Administration)

In order to understand the dynamics of change taking place in universities in South Africa today and their impact on teaching and learning, specifically at the University of the North, an understanding of the changing nature of relationships in education is essential. Teaching and learning must not be seen in isolation, but in the context of a universal paradigm shift manifest in all walks of life. The relationship between teacher and learner too has fundamentally changed. In today's 'opensystems' paradigm, relationships have become temporary, horizontalized, other-directed and complex in nature. It is in the light of these realities that meaningful teaching and learning must take place. In the context of today's rapidly changing environment, dominated by technocracy and characterised by alienation and misunderstanding, the need for knowledge and leadership, in and through the University of the North, is crucial. This, in turn, can only be achieved if the University becomes accessible and accountable to the community. The process of transforming anachronistic, closed and authoritarian structures on campus towards openness and accountability has been fraught with conflict and opportunism. The University of the North developed from a once universal contradiction, having been created as a political necessity, towards becoming an educational necessity. This process has witnessed attempts at reformation, open rebellion and the quest for total transformation. The search for meaningful alternatives, as mirrored by the broader struggle in society against the contradictions of apartheid policy, has impacted on all walks of life at the University. Teaching and learning became highly politicised, characterised by open conflict and alienation, resulting in destruction of the culture of learning. The present process of transformation on campus, involving all stakeholders, has led to many achievements in the search for new relationships and new meanings. It is essential that the University belong to the community. Standing on the edge of chaos, the University needs to set an example in leadership, in accessibility, relevance, and in the promotion of Africanisation as a didactic principle through dialogue, openness and the sharing of knowledge through practical action at the grass roots level. / Educational Studies / D. Ed. (Didactics)

In order to understand the dynamics of change taking place in universities in South Africa today and their impact on teaching and learning, specifically at the University of the North, an understanding of the changing nature of relationships in education is essential. Teaching and learning must not be seen in isolation, but in the context of a universal paradigm shift manifest in all walks of life. The relationship between teacher and learner too has fundamentally changed. In today's 'opensystems' paradigm, relationships have become temporary, horizontalized, other-directed and complex in nature. It is in the light of these realities that meaningful teaching and learning must take place. In the context of today's rapidly changing environment, dominated by technocracy and characterised by alienation and misunderstanding, the need for knowledge and leadership, in and through the University of the North, is crucial. This, in turn, can only be achieved if the University becomes accessible and accountable to the community. The process of transforming anachronistic, closed and authoritarian structures on campus towards openness and accountability has been fraught with conflict and opportunism. The University of the North developed from a once universal contradiction, having been created as a political necessity, towards becoming an educational necessity. This process has witnessed attempts at reformation, open rebellion and the quest for total transformation. The search for meaningful alternatives, as mirrored by the broader struggle in society against the contradictions of apartheid policy, has impacted on all walks of life at the University. Teaching and learning became highly politicised, characterised by open conflict and alienation, resulting in destruction of the culture of learning. The present process of transformation on campus, involving all stakeholders, has led to many achievements in the search for new relationships and new meanings. It is essential that the University belong to the community. Standing on the edge of chaos, the University needs to set an example in leadership, in accessibility, relevance, and in the promotion of Africanisation as a didactic principle through dialogue, openness and the sharing of knowledge through practical action at the grass roots level. / Educational Studies / D. Ed. (Didactics)