16 resultados para Diffusion process

em Deakin Research Online - Australia


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The paper examines the adoption and diffusion of Digital Television (DTV) in Australia and the United States, identifying historical, technical, regulatory, marketing, and other commonalities and differences that appear to be most significant to its adoption, as both countries have experienced a 'sluggish' diffusion and adoption of DTV so far. Using library research and borrowing the cross-impact matrix method from futures research, the authors develop J J events related to the various influences and groups of stakeholders that had shaped the policy making and adoption of DTV. We then carry out a comparative analysis between the two countries to make evident their impacts, strengths, and directions of influence. The authors suggest that the implementation of DTV in these two developed countries appears to be nearly identical. Even though Australian and US broadcasting models are fundamentally different, the diffusion process for DTV is primarily affected by the nature of digital technology and globalisation, two trends that may be diminishing the import of the nation-state in the technology adoption process. The paper concludes that these broader economic and technical events may have greater import to DTV's successful diffusion than do traditional, cultural, and nationalistic factors suggested in earlier comparative broadcast studies.

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The hydrogen diffusion and phase transformation in a titanium particle were studied based on thermodynamic calculation. The mechanisms of hydrogen diffusion in different phases (alpha-Ti, beta-Ti and TiHx) were analyzed. A mobility database was developed for titanium– hydrogen system based on the experimental works on hydrogen diffusion coefficient reported in literature and the fundamental of diffusion. To implement the calculation, a commercial software package for the simulation of diffusion-controlled phase transformation was used. The hydrogen diffusion process, hydrogen distribution, phase transformation and phase growth rate during hydrogenization of a titanium particle at temperatures of 560 K, 800K and 1000K were discussed. The thermodynamics and kinetics analysis provided quantitative insight into the diffusion process and improved the understanding of diffusion mechanism and phase transformation.

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We have introduced an in-situ Raman monitoring technique to investigate the crystallization process inside protein drops. In addition to a conventional vapour-diffusion process, a novel procedure which actively stimulates the evaporation from a protein drop during crystallization was also evaluated, with lysozyme as a model protein. In contrast to the conventional vapour-diffusion condition, the evaporation-stimulated growth of crystals was initiated in a simple dehydration scheme and completed within a significantly shorter time. To gain an understanding of crystallization behaviours under the conditions with and without such evaporation stimulation, confocal Raman spectroscopy combined with linear regression analysis was used to monitor both lysozyme and HEPES buffer concentrations in real time. The confocal measurements having a high spatial resolution and good linear response revealed areas of local inhomogeneity in protein concentration when the crystallization started. The acquired concentration profiles indicated that (1)ÿthe evaporation-stimulated crystallization proceeded with protein concentrations lower than those under conventional vapour diffusion, and (2)ÿcrystals under the evaporation-stimulated condition were noticeable within an early stage of crystallization before the protein concentration approached its maximum value. The HEPES concentration profiles, on the other hand, increased steadily towards the end of the process regardless of the conditions used for crystallization. In particular, the observed local inhomogeneities specific to protein distribution suggested an accumulation mechanism of protein molecules that initiates the nucleation of crystals.

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Use of hydrogen as a temporary alloying element in titanium alloys is an attractive approach to improve the mechanical properties of the materials, enhance processability and thereby reduce manufacturing costs. In this paper, the hydrogen diffusion process and the phase transformation both between titanium particles and in titanium sheets were computationally simulated to analyze the mechanism of hydrogen diffusion in different phases (α-Ti, β-Ti and TiHx). With the simulation based on the thermodynamics and kinetics, quantitative behaviors of the hydrogen diffusion and the phase transformation were analyzed. The simulation results provide an insight into the diffusion process and improve the fundamental understanding of the mechanism of diffusion and phase transformation.

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Use of hydrogen as a temporary alloying element in Ti alloys is an attractive approach to improve the mechanical properties of the materials, enhance processability and thereby reduce manufacturing costs. In this paper, the hydrogen diffusion process and the phase transformation both between Ti particles and in Ti sheets were simulated to analyze the mechanism of hydrogen diffusion in different phases (α-Ti, β-Ti and TiHx). With the simulation based on the kinetics and thermodynamics, quantitative behaviors of the hydrogen diffusion and the phase transformation were analyzed. The simulation results provide an insight into the diffusion process and improve the fundamental understanding of the mechanism of diffusion and phase transformation.

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Molecular dynamics simulation was employed to study the atomic interactions in titanium carbides and iron matrix containing carbon and titanium, which are significant for understanding the formation of titanium carbide cluster during precipitate process. The atoms trajectory and diffusion coefficients of carbon in titanium carbide were analyzed to provide a vacancy-exchanging mechanism and clarify the carbon concentration dependence of carbon diffusion in titanium carbide. The dependence of the formation of titanium carbide cluster in iron matrix on carbon was determined from the study of atoms diffusivity, cluster formation and formation energy of titanium carbide cluster. The simulation results provided insight into the carbon diffusion process and improved the understanding of the formation of titanium carbide cluster.

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At present, governments in many countries are actively engaged in the development of electronic trading and certification standards to enable the smooth operation of export markets. Standards and their usability underpin confidence in the operations of markets and their effective functioning. In institutional markets, an important role for government agencies lies in developing the initial specifications for standards for interoperable systems. Once these specifications are accepted, governments can then facilitate the eventual diffusion of a standard to the B2B marketplace. Acceptance of an industry standard can determine demand, which defines the viability of that market. In this paper, we describe an initiative by a government agency, the Australian Quarantine and Inspection Service (AQIS), in developing EXDOC, a standard for export documentation and the role that AQIS played in its implementation and diffusion. Our case study illustrates a successfully facilitated B2G implementation. It demonstrates how a standard can be supported and promulgated for the effective functioning of markets in the transition from manual to online export documentation. Once the overarching specifications for related industries have been established and diffused by government, opportunities arise for private sector markets to develop across these industries. Government agencies can promote the effective operation of standards for electronic markets. The EXDOC implementation and its iterations provide an exemplar of active engagement in the development of electronic trading and certification standards for an institutional market. Its successful diffusion provides a model of the implementation process for other export sectors and agencies.

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Constructivists often argue that International Organizations (IOs) diffuse norms throughout the international system. This article asks the question: if IOs promote and diffuse specific norms within world politics, where do these norms come from? In particular, this analysis seeks to formulate how IOs' identities emerge in issue areas where rationalist theories give limited explanation, such as the environment. This article posits that IOs interact with and consume norms from non-state actors such as transnational advocacy networks, a process overlooked by the constructivist analysis of institutions. This is examined through a case study of the World Bank's environmental identity where transnational advocacy networks played an important role in the Bank's shift towards sustainable development, through processes characterized here as direct and indirect socialization. This article demonstrates that the Bank's shift was more than instrumental as a result of this interaction, and that constructivists therefore need to examine the role of IOs as norm consumers as well as norm diffusers.

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In the present work, the carbon diffusion in steel, where the carbon diffusivity varies with the carbon content, was solved with the integral methods under the third boundary condition. The variation of carbon diffusivity in steel with the carbon content was described with two different functions ie. linear dependence and exponential dependence. The integral approximation for both cases was improved with the numerical computation to more accurately predict the carbon profiles. The integral solution is more accurate than the formulation based on the assumption of a constant diffusivity or those based on the assumption of a constant diffusivity and/or constant carbon content at part surface. It is also more easily used in practice than the numerical method to describe the carburising process and predict the carbon content at steel surface and carbon profiles in treated layer.

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This research project examined the diffusion of change within one Victorian TAFE Institute by engaging action research to facilitate implementation of e-mail technology. The theoretical framework involving the concepts of technology innovation and action research was enhanced with the aid of Rogers's (1983) model of the diffusion of the innovation process. Political and cultural factors made up the initiation phase of innovation, enabling the research to concentrate on the implementation phase of e-mail Roger's (1983) model also provided adopter categories that related to the findings of a Computer Attitude Survey that was conducted at The School of Mines and Industries Ballarat (SMB), now the University of Ballarat—TAFE Division since amalgamation on 1st January 1998. Despite management rhetoric about the need to utilise e-mail, Institute teaching staff lacked individual computers in their work areas and most were waiting to become connected to the Internet as late as 1997. According to the action research reports, many staff were resistant to the new e-mail facilities despite having access to personal computers whose numbers doubled annually. The action research project became focussed when action researchers realised that e-mail workshop training was ineffective and that staff required improved access. Improvement to processes within education through collaborative action research had earlier been achieved (McTaggart 1994), and this project actively engaged practitioners to facilitate decentralised e-mail training in the workplace through the action research spiral of planning, acting, observing and reflecting, before replanning. The action researchers * task was to find ways to improve the diffusion of e-mail throughout the Institute and to develop theoretical constructs. My research task was to determine whether action research could successfully facilitate e-mail throughout the Institute. A rich literature existed about technology use in education, technology teaching, gender issues, less about computerphobia, and none about 'e-mailphobia \ It seemed appropriate to pursue the issue of e-mailphobia since it was marginalised, or ignored in the literature. The major political and cultural influences on the technologising of SMB and e-mail introduction were complex, making it impossible to ascertain the relative degrees of influence held by Federal and State Governments, SMB's leadership or the local community, Nonetheless, with the implementation of e-mail, traditional ways were challenged as SMB's culture changed. E-mail training was identified as a staff professional development activity that had been largely unsuccessful. Action research is critical collaborative inquiry by reflective practitioners who are accountable for making the results of their inquiry public and who are self-evaluating of their practice while engaging participative problem-solving and continuing professional development (Zuber-Skerritt 1992, 1993). Action research was the methodology employed in researching e-mail implementation into SMB because it involved collaborative inquiry with colleagues as reflective practitioners. Thoughtful questions could best be explored using deconstructivist philosophy, in asking about the noise of silence, which issues were not addressed, what were the contradictions and who was being marginalised with e-mail usage within SMB. Reviewing literature on action research was complicated by its broad definition and by the variability of research (King & Lonnquist 1992), and yet action research as a research methodology was well represented in educational research literature, and provided a systematic and recognisable way for practitioners to conduct their research. On the basis of this study, it could be stated that action research facilitated the diffusion of e-mail technology into one TAFE Institute, despite the process being disappointingly slow. While the process in establishing the action research group was problematic, action researchers showed that a window of opportunity existed for decentralised diffusion of e-mail training,in preference to bureaucratically motivated 'workshops. Eight major findings, grouped under two broad headings were identified: the process of diffusion (planning, nature of the process, culture, politics) and outcomes of diffusion (categorising, e-mailphobia, the survey device and technology in education). The findings indicated that staff had little experience with e-mail and appeared not to recognise its benefits. While 54.1% did not agree that electronic means could be the preferred way to receive Institute memost some 13.7% admitted to problems with using the voice answering service on telephones. Some 43.3% thought e-mail would not improve their connectedness (how they related) to the Institute. A small percentage of staff had trouble with telephone voice-mail and a number of these were anxious computer users. Individualised tuition and peer support proved helpful to individual staff whom action researchers believed to be 'at risk', as determined from the results of a Computer Attitude Survey. An instructional strategy that fostered the development of self-regulation and peer support was valuable, but there was no measure of the effects of this action research program, other than in qualitative terms. Nevertheless, action research gave space to reflect on the nature of the underlying processes in adopting e-mail. Challenges faced by TAFE action researchers are integrally affected by the values within TAFE, which change constantly and have recently been extensive enough to be considered as a 'new paradigm'. The influence of competition policy, the training reform agenda and technologisation of training have challenged traditional TAFE values. Action research reported that many staff had little immediate professional reason to use e-mail Theoretical answers were submerged beneath practical professional concerns, which related back to how much time teachers had and whether they could benefit from e-mail. A need for the development of principles for the sound educational uses of e-mail increases with the internationalisation of education and an increasing awareness of cultural differences. The implications for conducting action research in TAFE are addressed under the two broad issues of power and pedagogy. Issues of power included gaining access, management's inability to overcome staff resistance to technology, changing TAFE values and using technology for conducting action research. Pedagogical issues included the recognition of educational above technological issues and training staff in action research. Finally, seventeen steps are suggested to overcome power and pedagogical impediments to the conduct of action research within TAFE. This action research project has provided greater insight into the difficulties of successfully introducing one culture-specific technology into one TAFE Institute. TAFE Institutes need to encourage more action research into their operations, and it is only then that -we can expect to answer the unanswered questions raised in this research project.

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Significant changes have occurred over the last decade within the Australian Vocational Education and Training (VET) system. Not least amongst these has been a shift from a predominantly traditional face-to-face classroom model of programme delivery to more flexible models informed by the needs of clients. To lead this revolution, in 1991 the Australian Commonwealth and State Ministers for Training established the Flexible Delivery Working Party. A series of reports followed that sought to develop a policy framework, including a definition of flexible delivery, and its principles and characteristics. Despite these efforts, project funding and national staff development initiatives, several difficulties have been experienced in the ‘take-up’ of flexible delivery; problems that we argue are related to how the dissemination of innovative practice is conceived. Specifically, the literature and research on the diffusion of innovations points to the efficacy of informal social networks ‘in which individuals adopt the new idea as a result of talking with other individuals who have already adopted it’ (Valente, 1995, p. ix). Following a discussion of these issues, the article concludes by arguing the need for research of innovative practice transfer within VET in Australia, using qualitative case study in order to develop an in-depth and rich description of the process, and facilitate greater understanding of how it works in practice.

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Composite LiFe0.4Mn0.6PO4/C microspheres are considered advanced cathode materials for electric vehicles and other high-energy density applications due to their advantages of high energy density and excellent cycling stability. LiFe0.4Mn0.6PO4/C microspheres have been produced using a double carbon coating process employing traditional industrial techniques (ball milling, spray-drying and annealing). The obtained LiFe0.4Mn0.6PO4 microspheres exhibit a high discharge capacity of around 166 mA h g-1 at 0.1 C and excellent rate capabilities of 132, 103, and 72 mA h g-1 at 5, 10, and 20 C, respectively. A reversible capacity of about 152 mA h g-1 after 500 cycles at a current density of 1 C indicates an outstanding cycling stability. The excellent electrochemical performance is attributed to the micrometer-sized spheres of double carbon-coated LiFe0.4Mn0.6PO4 nanoparticles with improved electric conductivity and higher Li ion diffusion coefficients, ensuring full redox reactions of all nanoparticles. The results show that the advanced high-energy density cathode materials can be produced using existing industry techniques.

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As pharmaceutical firms try to market their products and reduce costs, vertically integrated structureshamper innovation processes. Yet, pharmaceutical firms must innovate to compete. Outsourcing knowledgeintensive activities to knowledge process organizations (KPOs) serves to reduce innovation process obstacles.Grounded in diffusion theory and strategic management literature, this conceptual paper explores fourinterrelated strategic concepts: core competencies, economies of scale and scope, knowledge sharing,and learning. This paper claims that (a) accumulated core competencies of multinational pharmaceuticalcompanies (MPCs) erode over time and these companies become dependent on KPOs (b) MPCs mustunderstand how KPOs manage core competencies (c) economies of scope benefit KPOs enabling them tosustain competitive advantages for their MPC partners, meanwhile the benefits from economies of both scaleand scope shift from MPCs to KPOs (d) KPOs need to monitor their rate of learning to remain competitive.The paper identifies implications for industrial managers and directions for future research.