536 research outputs found
Corrosion between orthodontic archwires and bracket couples
Nickel-containing orthodontic wires have been reported to cause allergic reactions in sensitive individuals. An allergic reaction is related to corrosion of the alloys and subsequent leaching of nickel ions into the oral cavity. The purpose of this study was to determine if there is a significant difference in the corrosive potential of stainless steel, NiTi and TMA wires either alone or when coupled with a stainless steel bracket.;Using potentiostatic anodic polarization, the samples were tested in 0.9% NaCl solution at room temperature with neutral pH. The breakdown potentials of stainless steel, NiTi, TMA, and the stainless steel bracket were 600 mv, 1600 mv, \u3e2000 mv, and 200 mv respectively. When coupled with a stainless steel bracket, the breakdown potential for all three of the wire types was 200 mv. The stainless steel brackets proved to be the weak ling in the galvanic couple with the three wire types and the brackets have a significantly higher corrosive potential than any of the wires themselves
The Economic Value of Rebuilding Fisheries
The global demand for protein from seafood –- whether wild, caught or cultured, whether for direct consumption or as feed for livestock –- is high and projected to continue growing. However, the ocean's ability to meet this demand is uncertain due to either mismanagement or, in some cases, lack of management of marine fish stocks. Efforts to rebuild and recover the world's fisheries will benefit from an improved understanding of the long-term economic benefits of recovering collapsed stocks, the trajectory and duration of different rebuilding approaches, variation in the value and timing of recovery for fisheries with different economic, biological, and regulatory characteristics, including identifying which fisheries are likely to benefit most from recovery, and the benefits of avoiding collapse in the first place. These questions are addressed in this paper using a dynamic bioeconomic optimisation model that explicitly accounts for economics, management, and ecology of size-structured exploited fish populations. Within this model framework, different management options (effort controls on small-, medium-, and large-sized fish) including management that optimises economic returns over a specified planning horizon are simulated and the consequences compared. The results show considerable economic gains from rebuilding fisheries, with magnitudes varying across fisheries
Symbolic interactionism and the cell information board: challenging the wisdom of systems
Claudio Ciborra in “The Labyrinths of Information: Challenging the Wisdom of Systems” argues that the position of information and communications technology (ICT) in organizations requires a shift from the present focus on the “scientific paradigm” to an “alternative centre of gravity: human existence in everyday life”. This paper takes up Ciborra’s challenge by examining the focal point of social interaction during a longitudinal study of engaged scholarship in an Irish multinational subsidiary. During this study there was a gradual realization that the main locus of interaction was the cell information board. It was here that people gathered to assimilate digital information sources and transform these into “acts” including workpractice improvements. The paper seeks to answer the following question: how does symbolic interactionism enable the conceptualization of an information system as a sign-action system? The work makes a contribution by examining a supply chain information system as a form of symbolic action. The study challenges us to view information systems as not primarily being the IT artifact but pertaining first and foremost to human activity as its very core
Short interval management and the quest for process innovation: something new or déjà vu
Ireland still punches way above its weight internationally attracting 2% of total global foreign direct investment (FDI) in 2008 which amounted to circa €2 billion (IDA, 2009). The focus of the IDA (Industrial Development Authority which is responsible for foreign direct investment in Ireland) is on three strategic pillars: Global Services, High Technology Manufacturing and RD&I (Research Development and Innovation). Consequently innovation in manufacturing processes is a vital ingredient to providing sustainable MNC (Multinational Corporation) subsidiaries in the country. The work is presented in the context of a case study of innovation in APC Ireland, a subsidiary of the critical power and cooling services division of the Schneider Electric Corporation. Furthermore the paper will describe the utilization of a novel form of action research recently proposed to the IS community by Mårtensson & Lee (2004) which they call dialogical AR.. The central aim of this paper is to answer the following research question: can short interval management (SIM) support process innovation? The proposed structure of the paper is as follows. Firstly the background review will argue that SIM is not dealt with in the current literature and as a result has the potential to contribute to the conference theme. Then the longitudinal case study of a multi-national corporation together with the research approach will be outlined. An overview of the SIM process will be then presented followed by a discussion of the implications
The phenomenology of time: reflections from the Lebenswelt
The aim of this study is to reflect on how time was perceived by different actors during a longitudinal study of innovation in the lebenswelt –in this case a multi-national subsidiary (Costello, 2010). It aims to address the call by Markus (2000) that information systems (IS) research must incorporate the concepts of both history and time in their management and organization studies
Dialogical Action Research: A Case Study
Action Research (AR) originated from the work of Kurt Lewin during the 1940s and has been summarised as an approach that “combines theory and practice (and researchers and practitioners) through change and reflection in an immediate problematic situation within a mutually acceptable ethical framework” (Avison et al., 1999 p 94). The application of AR has not been without controversy particularly in debates with positivist science on the justification and generation of knowledge. These arguments were addressed by Susman & Evered (1978) in their influential description of AR as consisting of a cyclical process involving five phases: diagnosing, action planning, action taking, evaluating, and specifying learning. The focus of AR is to address real-life problems through intervention together with the research objective of making a contribution to knowledge. Coghlan and Brannick (2005 p 125) emphasise the importance of the social and academic context in which action research is carried out
Proposing a Meta-Theoretical Framework for Innovation Research
The importance of theory in the management discipline is the subject of ongoing debate and there have been recent calls for novel conceptualizations to stimulate research. In the area of innovation, one of the main conclusions of the influential Minnesota studies was the need to develop a metatheory. This paper examines the role of theory in the development of the research agenda for the area of innovation. Our approach is to build on the seminal work of the Minnesota studies and on the innovation perspectives of Carl Slappendel. The result of the study is a proposition that Ecological Systems Theory (EST) addresses many of the gaps that emerged from the analysis of the literature. Consequently the paper makes a contribution by developing a meta-theoretical framework for the study of innovation derived from the EST schemata
The phenomenology of time: reflections from the Lebenswelt
The aim of this study is to reflect on how time was perceived by different actors during a longitudinal study of innovation in the lebenswelt –in this case a multi-national subsidiary (Costello, 2010). It aims to address the call by Markus (2000) that information systems (IS) research must incorporate the concepts of both history and time in their management and organization studies
Beyond RBV and KBV to an innovation-based view of the firm
The quest to understand sources of sustained competitive advantage is still a major area of interest to both researchers and practitioners. The central thesis of this paper is that the resource-based view of the firm and the knowledge-based view of the firm require updating to an innovation-based view. This novel hypothesis of the firm is informed by a review of relevant literature and an empirical study of innovation management. The ICT revolution has a major impact on business and society resulting in an opening of the firm’s boundaries and increasing the digitalization of organizations. We utilize a grounded theory approach to the case study based in the Irish subsidiary of a multi-national corporation where innovation emerged as a key differentiator. Five empirical indicators of a firm’s propensity to harness innovation in order to generate sustained competitive advantage are proposed: management of paradox, degree of openness, the dilemma of initiation and implementation, nontechnological nature and technological nature. The paper contributes to advancing theory by advocating and developing an innovation-based view of the firm. Such a view is needed as innovation is now regarded by scholars and practitioners as being the driver of competitive advantage for the modern organization
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