Peter E Johansson

Formation of Fe(III) oxyhydroxide colloids in freshwater and brackish seawater, with incorporation of phosphate and calcium

Abstract The formation of Fe(III) oxyhydroxide colloids by oxidation of Fe(II) and their subsequent aggregation to larger particles were studied in laboratory experiments with natural water from a freshwater lake and a brackish coastal sea. Phosphate was incorporated in the solid phase during the course of hydrolysis of iron. The resulting precipitated amorphous Fe(III) oxyhydroxide phases were of varying composition, depending primarily on the initial dissolved Fe/P molar ratio, but with little influence by salinity or concentration of calcium ions. The lower limiting Fe/P ratio found for the solid phase suggests the formation of a basic Fe(III) phosphate compound with a stoichiometric Fe/P ratio of close to two. This implies that an Fe/P stoichiometry of ≈2 ultimately limits the capacity of precipitating Fe(III) to fix dissolved phosphate at oxic/anoxic boundaries in natural waters. In contrast to phosphorus, the uptake of calcium seemed to be controlled by sorption processes at the surface of the iron-rich particles formed. This uptake was more efficient in freshwater than in brackish water, suggesting that salinity restrains the uptake of calcium by newly formed Fe(III) oxyhydroxides in natural waters. Moreover, salinity enhanced the aggregation rate of the colloids formed. The suspensions were stabilised by the presence of organic matter, although this effect was less pronounced in seawater than in freshwater. Thus, in seawater of 6 to 33 ‰S, the removal of particles was fast (removal half time 900 h). Overall, oxidation of Fe(II) and removal of Fe(III) oxyhydroxide particles were much faster in seawater than in freshwater. This more rapid turnover results in lower iron availability in coastal seawater than in freshwater, making iron more likely to become a limiting element for chemical scavenging and biologic production.

Beyond being present : learning-oriented leadership in the daily work of middle managers

Purpose – This paper aims to contribute to the understanding of learning-oriented leadership as being integrated in managers’ daily work. The particular focus is on managers’ efforts to change how work is carried out through indirect acts of influence. In their daily work, managers influence the organisation’s learning conditions in ways that go beyond face-to-face interaction. Neither the influencer nor those influenced are necessarily aware that they are engaged in learning processes. Design/methodology/approach – The research was part of a larger case study. The data set comprised interviews with nine middle managers about ways of working during a period of organisational change. A learning-theoretical analysis model was used to categorise managerial acts of influence. The key concept concerned pedagogic interventions. Findings – Two qualitatively different routes for indirect influence were identified concerning social and organisational structures: one aligning, that narrows organisational members’ d...

Bridging Boundaries: Middle Managers´ Pedagogic Interventions as Technology Leaders.

The aim of this chapter is to describe interventions that middle managers make when they strive, as technology leaders, to bridge intra-organizational boundaries in order to support new agile ways of working. Another aim is to discuss how these interventions may be understood as pedagogic interventions.By using qualitative methods in a case study approach concerning the software communication industry, the findings reveal interventions that focused on alignment through collaboration, interdependency, flexibility, and communication. These kinds of interventions are regarded here as an example of pedagogic managerial leadership. Managers take on development and learning as main collective work tasks because they want to influence knowledge creation and are aware of thelearning dimension of their work tasks.The aim of this chapter is to describe interventions that middle managers make when they strive, as technology leaders, to bridge intra-organizational boundaries in order to support new agile ways of working. Another aim is to discuss how these interventions may be understood as pedagogic interventions.By using qualitative methods in a case study approach concerning the software communication industry, the findings reveal interventions that focused on alignment through collaboration, interdependency, flexibility, and communication. These kinds of interventions are regarded here as an example of pedagogic managerial leadership. Managers take on development and learning as main collective work tasks because they want to influence knowledge creation and are aware of thelearning dimension of their work tasks.

Interactive research as a strategy for practice-based learning: Designing competence development and professional growth in local school practice.

This chapter focuses on the work of teachers and education administrators’ use of interactional learning strategy. Instead of being guided by external experts, an interactive and dialogic approach is enacted between researchers and practitioners, in promoting the developmental needs and capacities of educational practitioners and generating responses to problems arising in practice settings . It is held that these problems and what constitutes effective and appropriate solutions may be unknown and unknowable to external experts, which limits their capacity to provide direct and effective guidance and recommendations. Instead, practice-based responses arising through interactions between practitioners and researchers are more likely to be generative of effective responses, whilst building capacity to resolve subsequent problems. Factors shaping the likely success of these strategies are premised upon the degree by which the practitioners are ready to and are confident in their capacity to progress these interactions. The pedagogic dimensions of these interactions were promoted by the use of specific strategies that included meetings and sharing of concerns and potential responses through a facilitated process ordered by the researchers as external agents. It is through these interventions that collective learning is secured and commitments to remake practice are emphasised.

Conceptions and operational use of value and waste in lean manufacturing – an interpretivist approach

In this article, we explore how the key concepts of lean manufacturing, value, value adding and waste are conceived and operationally used by Lean trainers in operational work processes. A comparative case study with a mixed method approach, using an explanatory sequential design, was conducted. This means that a set of quantitative data were collected, which was followed by the collection of qualitative data with the purpose of explaining and understanding the quantitative measures. An interpretivist approach is used as a framework, which implies a perspective on contemporary operations management paradigms, such as lean manufacturing, as a continuous construction of inter-subjective experiences. What becomes evident in the empirical findings is that there are both similarities and differences in the Lean trainers conceptions and use of value adding and waste. The similarities and differences can be explained by variations in two dimensions: (a) the character of the work process, which ranges between mechanical and craftsmanship, and (b) Lean trainers approach to key concepts, which ranges between being rule-based and reflective. By using a research design where the concepts of value adding and waste were used simultaneously, and adopting an interpretivist approach on lean manufacturing, we were able to reveal conditions that in other cases remain hidden.

Innovative Quality Improvements in Operations

This book examines current and emerging challenges in manufacturing related to the ideal of developing production processes with variability and agility on one level of the system, combined with st ...

Showing Action in Pictures

One challenge for the global market is to overcome communication problems of different kinds. The largest communication problem is language, people speak different languages and have limited knowledge in other languages. This problem is central in manuals and instructions for assembly and installations. One hopeful solution is that pictures can replace verbal instructions. In this paper we will discuss how illustrations in flat perspective can be useful for showing action in drawings.

Organizing Viable Development Work in Operations

The aim of this chapter is to give an account of and discuss how viable development work can be organized and engage employees on all levels of an organization, which, depending on the specific needs, enables the emergence of both exploitation and exploration. A further aim is to describe the relationship between how development work is carried out and the opportunities afforded by such work for continuous learning of development work competence. The empirical material contains several examples of how employees are committed to improving their own operations, which in itself is an important prerequisite for a continuous work-integrated learning. However, the empirical findings presented in this chapter indicate that this is not a sufficient condition for the long-term development of skills relevant to pursuing structured development work. One conclusion to draw is that development work needs to be treated as a domain-specific competence in itself, which in turn needs to be distributed throughout the organization.

Making people’s work-Integrated relations visible : useable organisational images for managerial enabling of change

This paper examines the potential contribution of organisation images where there is a need to understand and lead change. It is theoretically based on the dual assumption that leaders and co-worke ...