403 research outputs found

    Time to be responsive in the process industry: a literature-based analysis of trends of change, solutions and challenges

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    The current uncertain and volatile business context is challenging firms worldwide, leading to the need to be responsive at a competitive cost. This trend is so substantial that it even affects industries traditionally competing in rather stable contexts, such as the process industry. Although the process industry includes multiple sectors with different technologies and processes, these share several aspects that make the industry as a whole distinctive to the discrete manufacturing industry. Based on a literature review, this study identifies and describes trends leading the process industry to the need for responsiveness, corresponding solutions to accommodate the need, and related challenges hindering the industrialization and diffusion of solutions in this industry. This study shows that trends, such as the uncertainty and volatility of market requirements, are challenging the process industry to develop reconfigurability solutions across multiple production levels. The development of reconfigurability solutions is hindered by modularity, integrability, co-ordination and collaboration challenges

    Synchronisation of material flows in mass-customised production systems: a literature-based classification framework and industrial application

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    The mass customisation strategy is needed by manufacturing companies to face the increasing variety and unpredictability of products required by customers. However, mass customisation may increase the complexity of managing manufacturing and production logistics activities, for example due to reduced product batch sizes. The synchronisation of material flows within the factory is emerging as a way to address this complexity, as it enables an effective and efficient implementation of mass customisation. Indeed, the fourth Industrial Revolution introduces new digital levers, which can be combined with traditional managerial levers to achieve the synchronisation of material flows within the factory. This study contributes to the rising stream of research on this topic. A systematic literature review was conducted, leading to the development of a classification framework of the levers supporting the synchronisation of material flows. The identified managerial levers are: storage of materials, feeding policy, and scheduling. The digital levers are: materials tracking, process tracking, data analytics, and assistance systems. The developed framework was operationalised in four industrial cases and applied as a tool to map their levers related to the synchronisation of material flows

    Comparing the effects of combined numerical and visuospatial psychoeducational trainings conducted by curricular teachers and external trainers. Preliminary evidence across kindergarteners

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    The aim of this study was to verify the efficacy of two pencil-and-paper trainings empowering numerical and visuo-spatial abilities in Italian five-year-old kindergarteners. Specifically, the trainings were respectively carried out by the curricular teacher or by an external trainer. The former received a specific training in order to use the psychoeducational programmes with her pupils, whereas the latter received a specific education about the role of numerical and visuo-spatial abilities for school achievement and she was also trained to use psychoeducational trainings in kindergarten schools. At pre-test and post-test nonverbal functions and numeracy knowledge were assessed through a battery of standardized tests. The results show that both the numerical psychoeducational programme and the visuo-spatial one are useful tools to enhance mathematical achievements in kindergarteners. However, when the trainings were proposed by the external trainer, the efficacy of the psychoeducational programmes was more significant. These outcomes seem to be related both to the expertise and the novelty effect of the external trainer on the classroom

    The unprecedented optical outburst of the quasar 3C 454.3. The WEBT campaign of 2004-2005

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    The radio quasar 3C 454.3 underwent an exceptional optical outburst lasting more than 1 year and culminating in spring 2005. The maximum brightness detected was R = 12.0, which represents the most luminous quasar state thus far observed (M_B ~ -31.4). In order to follow the emission behaviour of the source in detail, a large multiwavelength campaign was organized by the Whole Earth Blazar Telescope (WEBT). Continuous optical, near-IR and radio monitoring was performed in several bands. ToO pointings by the Chandra and INTEGRAL satellites provided additional information at high energies in May 2005. The historical radio and optical light curves show different behaviours. Until about 2001.0 only moderate variability was present in the optical regime, while prominent and long-lasting radio outbursts were visible at the various radio frequencies, with higher-frequency variations preceding the lower-frequency ones. After that date, the optical activity increased and the radio flux is less variable. This suggests that the optical and radio emissions come from two separate and misaligned jet regions, with the inner optical one acquiring a smaller viewing angle during the 2004-2005 outburst. Moreover, the colour-index behaviour (generally redder-when-brighter) during the outburst suggests the presence of a luminous accretion disc. A huge mm outburst followed the optical one, peaking in June-July 2005. The high-frequency (37-43 GHz) radio flux started to increase in early 2005 and reached a maximum at the end of our observing period (end of September 2005). VLBA observations at 43 GHz during the summer confirm theComment: 7 pages, 4 figures, to be published in A&

    Regulation of angiogenesis by a non-canonical Wnt-Flt1 pathway in myeloid cells

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    Myeloid cells are a feature of most tissues. Here we show that during development, retinal myeloid cells (RMCs) produce Wnt ligands to regulate blood vessel branching. In the mouse retina, where angiogenesis occurs postnatally, somatic deletion in RMCs of the Wnt ligand transporter Wntless results in increased angiogenesis in the deeper layers. We also show that mutation of Wnt5a and Wnt11 results in increased angiogenesis and that these ligands elicit RMC responses via a non-canonical Wnt pathway. Using cultured myeloid-like cells and RMC somatic deletion of Flt1, we show that an effector of Wnt-dependent suppression of angiogenesis by RMCs is Flt1, a naturally occurring inhibitor of vascular endothelial growth factor (VEGF). These findings indicate that resident myeloid cells can use a non-canonical, Wnt-Flt1 pathway to suppress angiogenic branching
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