553 research outputs found

    Characterization of a new dry drill-milling process of Carbon Fibre Reinforced Polymer laminates

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    Carbon Fibre Reinforced Polymer (CFRP) composites are widely used in aerospace applications that require severe quality parameters. To simplify the assembly operations and reduce the associated costs, the current trend in industry is to optimize the drilling processes. However, the machining of CFRP composites is very challenging compared with metals, and several defect types can be generated by drilling. The emerging process of orbital drilling can greatly reduce the defects associated with the traditional drilling of CFRP, but it is a more complex process requiring careful process parameters selection and it does not allow for the complete elimination of the thrust force responsible for delamination damage. As an alternative to traditional and orbital drilling, this work presents a new hole making process, where the hole is realized by a combination of drilling and peripheral milling performed using the same cutting tool following a novel tool path strategy. An original tool design principle is proposed to realize a new drill-milling tool, made of a first drilling and a subsequent milling portion. Two different tool configurations are experimentally tested to evaluate the performance of the newly-conceived combined drill-milling process. This process is quick and easy, and the experimental results show an improvement in the drilled hole quality

    Machining of composite materials

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    In this chapter, an overview of the main issues concerning drilling of polymer matrix fibrous composite materials is presented. These materials are widely used for parts manufacturing in the aerospace industry due to their high specific mechanical properties and low weight, and require extensive drilling processes, for e.g. joining. A proper optimization of the drilling process can substantially improve parts quality, often affected by diverse faults generated during the process. As several parameters are involved in FRP composites drilling, and complex phenomena occur, which are completely different from metal cutting, such optimization is a challenging task. To examine the relevant issues, the influence of tool geometry and technological parameters on thrust force, torque and tool wear are discussed, as well as their role in delamination. These aspects are illustrated with particular reference to drilling of carbon fiber reinforced polymer (CFRP) composites, which are widely employed in the aerospace industry

    Data of cost-optimal solutions and retrofit design methods for school renovation in a warm climate

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    Abstract"Efficient Solutions and Cost-Optimal Analysis for Existing School Buildings" (Paolo Maria Congedo, Delia D’Agostino, Cristina Baglivo, Giuliano Tornese, Ilaria Zacà) [1] is the paper that refers to this article. It reports the data related to the establishment of several variants of energy efficient retrofit measures selected for two existing school buildings located in the Mediterranean area. In compliance with the cost-optimal analysis described in the Energy Performance of Buildings Directive and its guidelines (EU, Directive, EU 244,) [2,3], these data are useful for the integration of renewable energy sources and high performance technical systems for school renovation. The data of cost-efficient high performance solutions are provided in tables that are explained within the following sections.The data focus on the describe school refurbishment sector to which European policies and investments are directed. A methodological approach already used in previous studies about new buildings is followed (Baglivo Cristina, Congedo Paolo Maria, D׳Agostino Delia, Zacà Ilaria, 2015; IlariaZacà, Delia D’Agostino, Paolo Maria Congedo, Cristina Baglivo; Baglivo Cristina, Congedo Paolo Maria, D’Agostino Delia, Zacà Ilaria, 2015; Ilaria Zacà, Delia D’Agostino, Paolo Maria Congedo, Cristina Baglivo, 2015; Paolo Maria Congedo, Cristina Baglivo, IlariaZacà, Delia D’Agostino,2015) [4–8]. The files give the cost-optimal solutions for a kindergarten (REF1) and a nursery (REF2) school located in Sanarica and Squinzano (province of Lecce Southern Italy). The two reference buildings differ for construction period, materials and systems.The eleven tables provided contain data about the localization of the buildings, geometrical features and thermal properties of the envelope, as well as the energy efficiency measures related to walls, windows, heating, cooling, dhw and renewables. Output values of energy consumption, gas emission and costs are given for a financial and a macro-economic analysis.This data article provides 288 and 96 combinations for REF1 and REF2, respectively. The output values are obtained using the software ProCasaClima 2015v.2.0

    Temperature measurements for the tool wear and hole quality assessment during drilling of CFRP/CFRP stacks

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    Carbon Fiber Reinforced Polymer (CFRP) laminates are widely employed in the aerospace industry as they are lightweight materials with high mechanical strength. Drilling, that is the most common machining process for CFRP parts, may induce several types of defects in the laminates. This paper is aimed at the correlation of parameters representative of the hole quality and tool wear with data from thermographic analysis with the aim to investigate the possibility to assess the hole quality in real time, and to detect the need for tool replacement without physical measurements on the tool. The developed procedure is applied to the holes produced by two different geometry tools

    Author Correction: Gluten consumption and inflammation affect the development of celiac disease in at-risk children

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    The original version of this Article contained an error in the spelling of the authors Renata Auricchio, Ilaria Calabrese, Martina Galatola, Donatella Cielo, Fortunata Carbone, Marianna Mancuso, Giuseppe Matarese, Riccardo Troncone, Salvatore Auricchio & Luigi Greco which were incorrectly given as Auricchio Renata, Calabrese Ilaria, Galatola Martina, Cielo Donatella, Carbone Fortunata, Mancuso Marianna, Matarese Giuseppe, Troncone Riccardo, Auricchio Salvatore & Greco Luigi. The original article has been corrected

    Environmental policies and social impacts. Suggestions from Europeans cities

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    Are we really sure that green and sustainable are always good for everyone? Ilaria Beretta tries to go beyond the rhetoric of sustainability to understand more deeply the interconnection between economy, society and environment in urban contexts, in the belief that only empirical research and the analysis of data can lead to a correct reading, which is as objective as possible, of the complex reality in which we live. The author, through a comparison between European and U.S. American cities, focuses in particular on policies related to climate change and land use, showing how these, if not properly monitored in their social effects, risk contributing to the tightening of social inequalities, through processes such as ecological and green gentrification. The volume is structured in three parts. In the first section, she illustrates the main European Union’s sustainability and environmental urban policies, focusing on climate change and land use strategies. The second chapter provides a conceptual framework through the environmental justice paradigm, as it applies in Europe and in U.S. Finally, the third chapter offers an empirical analysis of ecological and green gentrification processes, comparing American and European realities, and highlighting how context-specific differences can have profound effects on the manifestation (or not) of these phenomena

    Potential cause-effect relationship between insulin autoimmune syndrome and alpha lipoic acid: Two case reports

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    Objectives: Insulin autoimmune syndrome (IAS) or Hirata disease is a rare cause of autoimmune hypoglycemia with apparent high insulin levels and anti-insulin autoantibodies and was first described by Hirata in Japan in 1970. IAS cases are usually related to exposure to sulfhydryl-containing drugs, which stimulate the production of insulin autoantibodies. Among sulfhydryl-containing compounds, alpha lipoic acid (ALA) has recently emerged as a cause of IAS. After the first observations of ALA-induced IAS were reported in Japan in 2006, an increasing number of cases related to ALA administration have been described. An Italian group recently reported on six cases of IAS of which one was associated with HLA-DRB1*04:06 and the remaining five with HLA-DRB1*04:03. This suggests that the latter is potentially involved in the genetic susceptibility of people of European descent to IAS. Methods: Here, we describe two new cases of IAS in women that were triggered by ALA. Results: Both cases are associated with HLA-DRB1*04:03 and confirm the evidence that HLA-DRB1*04:03 rather than HLA-DRB1*04:06 is specifically related to IAS susceptibility in Europeans. Conclusions: Case reports of ALA-induced hypoglycemic episodes highlight the need for greater care in prescribing ALA supplementation as well as the identification of specific and personalized therapeutic targets
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