78 research outputs found

    The SiRi Particle-Telescope System

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    A silicon particle-telescope system for light-ion nuclear reactions is described. In particular, the system is designed to be optimized for level density and gamma-ray strength function measurements with the so-called Oslo method. Eight trapezoidal modules are mounted at 5 cm distance from the target, covering 8 forward angles between theta = 40 and 54 degrees. The thin front dE detectors (130 micrometer) are segmented into eight pads, determining the reaction angle for the outgoing charged ejectile. Guard rings on the thick back E detectors (1550 micrometer) guarantee low leakage current at high depletion voltage.Comment: 6 pages, 8 figure

    First fabrication of full 3D-detectors at SINTEF

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    International audienceA knowledge of the mechanical properties of bacterial biofilms is required to more fully understand the processes of biofilm formation such as initial adhesion or detachment. The main contribution of this article is to demonstrate the use of homogenization techniques to compute mechanical parameters of Pseudomonas aeruginosa PAO1 biofilms. For this purpose, homogenization techniques are used to analyze freeze substitution electron micrographs of the biofilm cross-sections. The concept of a representative volume element and the study about his representativeness allows us to determine the optimal size in order to analyze these biofilm images. Results demonstrate significant heterogeneities with respect to stiffness and these can be explained by varying cell density distribution throughout the bacterial biofilms. These stiffness variations lead to different mechanical properties along the height of the biofilm. Moreover, a numerical shear stress test shows the impact of these heterogeneities on the detachment process. Several modes of detachment are highlighted according to the local strain energy in the different parts of the biofilm. Knowing where, and how, a biofilm may detach will allow better prediction of accumulation and biomass detachment

    Desperately seeking niches: Grassroots innovations and niche development in the community currency field

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    The sustainability transitions literature seeks to explain the conditions under which technological innovations can diffuse and disrupt existing socio-technical systems through the successful scaling up of experimental ‘niches’; but recent research on ‘grassroots innovations’ argues that civil society is a promising but under-researched site of innovation for sustainability, albeit one with very different characteristics to the market-based innovation normally considered in the literature. This paper aims to address that research gap by exploring the relevance of niche development theories in a civil society context. To do this, we examine a growing grassroots innovation – the international field of community currencies – which comprises a range of new socio-technical configurations of systems of exchange which have emerged from civil society over the last 30 years, intended to provide more environmentally and socially sustainable forms of money and finance. We draw on new empirical research from an international study of these initiatives comprising primary and secondary data and documentary sources, elite interviews and participant observation in the field. We describe the global diffusion of community currencies, and then conduct a niche analysis to evaluate the utility of niche theories for explaining the development of the community currency movement. We find that some niche-building processes identified in the existing literature are relevant in a grassroots context: the importance of building networks, managing expectations and the significance of external ‘landscape’ pressures, particularly at the level of national-type. However, our findings suggest that existing theories do not fully capture the complexity of this type of innovation: we find a diverse field addressing a range of societal systems (money, welfare, education, health, consumerism), and showing increasing fragmentation (as opposed to consolidation and standardisation); furthermore, there is little evidence of formalised learning taking place but this has not hampered movement growth. We conclude that grassroots innovations develop and diffuse in quite different ways to conventional innovations, and that niche theories require adaptation to the civil society context

    Building adaptive capacity to climate change in tropical coastal communities

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    To minimize the impacts of climate change on human wellbeing, governments, development agencies, and civil society organizations have made substantial investments in improving people's capacity to adapt to change. Yet to date, these investments have tended to focus on a very narrow understanding of adaptive capacity. Here, we propose an approach to build adaptive capacity across five domains: the assets that people can draw upon in times of need; the flexibility to change strategies; the ability to organize and act collectively; learning to recognize and respond to change; and the agency to determine whether to change or not

    3D interconnect technologies for advanced MEMS/NEMS applications

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    3D integration and wafer level packaging (WLP) with through-silicon vias offer benefits like reduced footprint and improved performance. CMOS imaging sensors is one of the first successful introductions of a product with TSVs on the market, and 3D integrated memory stacks are expected to follow soon. Also sensor and actuator systems based on micro- and nano-electromechanical systems (MEMS/NEMS) will greatly benefit from WLP and 3D integration of the transducers and their readout and controller ICs. Ultimately, heterogeneous integration of different device technologies will allow the fabrication of MEMS/IC and NEMS/IC products with new and improved functionalities. For this to become a reality, cost-effective and reliable 3D integration technologies need to be developed. This paper gives an overview and reports on the current status of 3D interconnect technologies that will enable 3D integration for advanced MEMS/NEMS applications

    Design, Simulation, Fabrication, and Preliminary Tests of 3D CMS Pixel Detectors for the Super-LHC

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    The Super-LHC upgrade puts strong demands on the radiation hardness of the innermost tracking detectors of the CMS, which cannot be fulfilled with any conventional planar detector design. The so-called 3D detector architectures, which feature columnar electrodes passing through the substrate thickness, are under investigation as a potential solution for the closest operation points to the beams, where the radiation fluence is estimated to reach 10 16neq/cm2. Two different 3D detector designs with CMS pixel readout electronics are being developed and evaluated for their advantages and drawbacks. The fabrication of full-3D active edge CMS pixel devices with p-type substrate has been successfully completed at SINTEF. In this paper, we study the expected post-irradiation behaviors of these devices with simulations and, after a brief description of their fabrication, we report the first leakage current measurement results as performed on wafer. © 2010 IEEE
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