1,627 research outputs found

    The Jahn-Teller active fluoroperovskites ACrF3A\mathrm{CrF_3} A=Na+,K+A=\mathrm{Na^+},\mathrm{K^+}: thermo- and magneto optical correlations as function of the AA-site

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    Chromium (II) fluoroperovskites ACrF3(A=Na+,K+)A\mathrm{CrF_3}(A\mathrm{=Na^+,K^+}) are strongly correlated Jahn-Teller active materials at low temperatures. In this paper, we examine the role that the AA-site ion plays in this family of fluoroperovskites using both experimental methods (XRD, optical absorption spectroscopy and magnetic fields) and DFT simulations. Temperature-dependent optical absorption experiments show that the spin-allowed transitions E2E_2 and E3E_3 only merge completely for AA= Na at 2 K. Field-dependent optical absorption measurements at 2 K show that the oscillating strength of the spin-allowed transitions in NaCrF3\mathrm{NaCrF_3} increases with increasing applied field. Direct magneto-structural correlations which suppress the spin-flip transitions are observed for KCrF3{\rm KCrF_3} below its Ne\'el temperature. In NaCrF3{\rm NaCrF_3} the spin-flip transitions vanish abruptly below 9 K revealing magneto-optical correlations not linked to crystal structure changes. This suggests that as the long range ordering is reduced local JT effects in the individual CrF64{\rm CrF_6^{4-}} octahedra take control of the observed behavior. Our results show clear deviation from the pattern found for the isoelectronic AxMnF3+xA_x{\rm MnF}_{3+x} system. The size of the AA-site cation is shown to be central in dictating the physical properties and phase transitions in ACrF3A{\rm CrF}_3, opening up the possibility of varying the composition to create novel states of matter with tuneable properties

    Local Nodes in Global Networks: The Geography of Knowledge Flows in Biotechnology Innovation

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    The literature on innovation and interactive learning has tended to emphasize the importance of local networks, inter-firm collaboration and knowledge flows as the principal source of technological dynamism. More recently, however, this view has come to be challenged by other perspectives that argue for the importance of non-local knowledge flows. According to this alternative approach, truly dynamic economic regions are characterized both by dense local social interaction and knowledge circulation, as well as strong inter-regional and international connections to outside knowledge sources and partners. This paper offers an empirical examination of these issues by examining the geography of knowledge flows associated with innovation in biotechnology. We begin by reviewing the growing literature on the nature and geography of innovation in biotechnology research and the commercialization process. Then, focusing on the Canadian biotech industry, we examine the determinants of innovation (measured through patenting activity), paying particular attention to internal resources and capabilities of the firm, as well as local and global flows of knowledge and capital. Our study is based on the analysis of Statistics Canada’s 1999 Survey of Biotechnology Use and Development, which covers 358 core biotechnology firms. Our findings highlight the importance of in-house technological capability and absorptive capacity as determinants of successful innovation in biotechnology firms. Furthermore, our results document the precise ways in which knowledge circulates, in both embodied and disembodied forms, both locally and globally. We also highlight the role of formal intellectual property transactions (domestic and international) in promoting knowledge flows. Although we document the importance of global networks in our findings, our results also reveal the value of local networks and specific forms of embedding. Local relational linkages are especially important when raising capital—and the expertise that comes with it—to support innovation. Nevertheless, our empirical results raise some troubling questions about the alleged pre-eminence of the local in fostering innovation

    Improving technology transfer through national systems of innovation: climate relevant innovation-system builders (CRIBs)

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    The Technology Executive Committee (TEC) of the United Nations Framework Convention on Climate Change (UNFCCC) recently convened a workshop seeking to understand how strengthening national systems of innovation (NSIs) might help to foster the transfer of climate technologies to developing countries. This article reviews insights from the literatures on Innovation Studies and Socio-Technical Transitions to demonstrate why this focus on fostering innovation systems has potential to be more transformative as an international policy mechanism for climate technology transfer than anything the UNFCCC has considered to date. Based on insights from empirical research, the article also articulates how the existing architecture of the UNFCCC Technology Mechanism could be usefully extended by supporting the establishment of CRIBs (climate relevant innovation-system builders) in developing countries – key institutions focused on nurturing the climate-relevant innovation systems and building technological capabilities that form the bedrock of transformative, climate-compatible technological change and development

    The regional economic impact of more graduates in the labour market: a “micro-to-macro” analysis for Scotland

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    This paper explores the system-wide impact of graduates on the regional economy. Graduates enjoy a significant wage premium, often interpreted as reflecting their greater productivity relative to non-graduates. If this is so there is a clear and direct supply-side impact of HEI activities on regional economies. We use an HEI-disaggregated computable general equilibrium model of Scotland to estimate the impact of the growing proportion of graduates in the Scottish labour force that is implied by the current participation rate and demographic change, taking the graduate wage premium in Scotland as an indicator of productivity enhancement. While the detailed results vary with alternative assumptions about the extent to which wage premia reflect productivity, they do suggest that the long-term supply-side impacts of HEIs provide a significant boost to regional GDP. Furthermore, the results suggest that the supply-side impacts of HEIs are likely to be more important than the expenditure impacts that are the focus of most HEI impact studies

    Canted antiferromagnetism in high purity NaFeF3\mathrm{NaFeF_3} prepared by a novel wet-chemical synthesis method

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    We report a novel synthesis method for, and structural and magnetic characterization of the fluoroperovskite NaFeF3\mathrm{NaFeF_3}. We have developed a wet-chemical method that allows preparation of large volumes of air-sensitive fluoroperovskites with high purity. NaFeF3\mathrm{NaFeF_3} has a N\'eel temperature (TNT_N) of 90 K and a Weiss constant (θ\theta) of -124 K, corresponding to dominant antiferromagnetic interactions. Below TNT_N, a slight difference is observed between zero-field and field cooled samples, indicating spin-canting and weak ferromagnetism. AC magnetometry confirms that weak ferromagnetism is inherent to NaFeF3\mathrm{NaFeF_3} and not due to impurities. From powder neutron diffraction data, we describe the magnetic structure precisely as a weakly canted G-type (magnetic space group PnmaPn'ma'). A ferromagnetic component is allowed in PnmaPn'ma', however, this component may be absent in zero magnetic fields and is too small to be confirmed on the basis of powder neutron diffraction data.Comment: 9 pages, 10 figure

    Examining the Connections within the Startup Ecosystem: A Case Study of St. Louis

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    This paper documents the resurgence of entrepreneurial activity in St. Louis by reporting on the collaboration and local learning within the startup community. This activity is happening both between entrepreneurs and between organizations that provide support, such as mentoring and funding, to entrepreneurs. As these connections deepen, the strength of the entrepreneurial ecosystem grows. Another finding from the research is that activity-based events, where entrepreneurs have the chance to use and practice the skills needed to grow their businesses, are most useful. St. Louis provides a multitude of these activities, such as Startup Weekend, 1 Million Cups, Code Until Dawn, StartLouis, and GlobalHack. Some of these are St. Louis specific, but others have nationwide or global operations, providing important implications for other cities

    Innovation and Control: Universities, the Knowledge Economy, and the Authoritarian State in China

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    Like many other education systems in the world, Chinese education has undergone various reforms in order to adapt to the challenges that are perceived to emanate from the knowledge economy. Central to this transformation is the concept of ‘innovation’, which is to guide the country on its path from a production economy to a knowledge economy. Chinese policymakers have been targeting the higher education sector both as a motor for innovation and as a realm to be innovated, and have invested heavily in the sector’s internationalization, above all in the form of international collaboration and student mobility, affecting higher education and academia worldwide. However, a number of structural and political constraints delimit the directions that innovation can take, both within Chinese education in general and within Chinese higher education. The article takes stock of these constraints and assesses the potential for innovation in Chinese higher education in terms of the underlying school system, exam and recruitment policies, the (re-)organization of universities, as well as the universities’ and science system’s performance according to indicators of innovation. The article then identifies four ‘Chinese innovation dilemmas’, that is, educational policies and developments that are to spur innovation but run counter to existing structures and practices of educational, social, and political governance: ideological control versus creativity; state planning versus grassroots innovation; old-boy networks versus anti-corruption; and exam-based student recruitment versus flexible recruitment

    An exploratory study into everyday problem solving in the design process of medical devices

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    We investigated accounts of how individuals in public and private organisations operating in the medical device industry use different forms of capital (social e.g. networks and cultural e.g. knowledge) to solve design based problems. We define capital as resources embedded in social networks, knowledge or economic wealth (Bourdieu, 1986). Data were collected from interviews and written diaries from individuals involved in the design process of medical devices using interpretative analysis. Inferences made from our analyses suggested that individuals working in organisations who successfully solve problems may do so by using both social and cultural capital and so may be more likely to engage in innovative activity than others. These exploratory findings suggest workers in large organisations may have the capability to use a greater level of in-house social and cultural capital, whereas those in smaller organisations may be more reliant on high levels of social capital in order to ‘tap into’ cultural capital beyond organisational boundaries
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