a tailored maintenance management system to control spare parts life cycle

Abstract The maintenance of complex production systems became increasingly crucial to ensure the competitiveness of companies and service level to their clients. Because of product customization the number of mechanical and electrical components and functional groups of manufacturing lines enhanced with their complexity. To face this concern, the physical and logical design of such systems is typically partitioned among several groups of engineers and designers. Consequently, a holistic awareness of the whole project is lacking and the maintenance of such systems becomes even more challenging. In view of this, new tailored support-decision tools able to manage and control the life cycle of spare parts from their design, throughout the run time, and to their failure and replacement are necessary. This paper illustrates an original maintenance management system (MMS) resulting by the combination of different computerized tools able to integrate the information flow behind the life cycle of a generic component. The proposed system supports coordination among groups of engineers and practitioners through graphic user interfaces (GUIs) and performance i.e. cost, reliability, dashboards, which lead decision-making from the design phase to the planning of maintenance tasks along the life of the manufacturing line. These tools are validated with a real-world instance from the tobacco industry which allows assessing how components belonging to the same functional group may differently behave over their life cycle. The results suggest that the holistic awareness on the whole manufacturing system provided by the proposed MMS can support task design and schedule of maintenance actions providing the reduction of more than 20% of the total cost and time for maintenance actions. The practical example shown contributes to shed light on the potentials of new paradigms for maintenance management in the industry 4.0

Fast Switching Electrochromic Devices Containing Optimized BEMA/PEGMA Gel Polymer Electrolytes

An optimized thermoset gel polymer electrolyte based on Bisphenol A ethoxylate dimethacrylate and Poly(ethylene glycol) methyl ether methacrylate (BEMA/PEGMA) was prepared by facile photo-induced free radical polymerisation technique and tested for the first time in electrochromic devices (ECD) combining WO3 sputtered on ITO as cathodes and V2O5 electrodeposited on ITO as anodes. The behaviour of the prepared ECD was investigated electrochemically and electro-optically. The ECD transmission spectrum was monitored in the visible and near-infrared region by varying applied potential. A switching time of ca. 2 s for Li+ insertion (coloring) and of ca. 1 s for Li+ de-insertion (bleaching) were found. UV-VIS spectroelectrochemical measurements evidenced a considerable contrast between bleached and colored state along with a good stability over repeated cycles. The reported electrochromic devices showed a considerable enhancement of switching time with respect to the previously reported polymeric ECD indicating that they are good candidates for the implementation of intelligent windows and smart displays

Fatigue analysis-based numerical design of stamping tools made of cast iron

This work concerns stress and fatigue analysis of stamping tools made of cast iron with an essentially pearlitic matrix and containing foundry defects. Our approach consists at first, in coupling the stamping numerical processing simulations and structure analysis in order to improve the tool stiffness geometry for minimizing the stress state and optimizing their fatigue lifetime. The method consists in simulating the stamping process by considering the tool as a perfect rigid body. The estimated contact pressure is then used as boundary condition for FEM structure loading analysis of the tool. The result of this analysis is compared with the critical stress limit depending on the automotive model. The acceptance of this test allows calculating the fatigue lifetime of the critical zone by using the S–N curve of corresponding load ratio. If the prescribed tool life requirements are not satisfied, then the critical region of the tool is redesigned and the whole simulation procedures are reactivated. This method is applied for a cast iron EN-GJS-600-3. The stress-failure (S–N) curves for this material is determined at room temperature under push pull loading with different load ratios R0σmin/σmax0−2, R0−1 and R00.1. The effects of the foundry defects are determined by SEM observations of crack initiation sites. Their presence in tested specimens is associated with a reduction of fatigue lifetime by a factor of 2. However, the effect of the load ratio is more important

Polymer electrolyte membranes and process for the production thereof

The process for the production of a polymer electrolyte membrane, comprises the successive steps of: preparing a mixed solution of a Room Temperature Ionic Liquid (RTIL), at least one alkaline metal salt and a photosensitive hydrogen abstracting component at a temperature in the range 20 to 70 °C, wherein the RTIL is a compound consisting of at least one organic cation and at least one organic or inorganic anion; adding to the solution a polymeric material at a temperature in the range of 20-70 °C; blending the solution added with the polymeric material at a temperature in the range of 70-140 °C to get a uniform mixture; pressing the mixture between two sheets at a temperature in the range of 60 - 150 °C and a pressure in the range of 20 - 80 bar, so that a film is formed; and exposing the film to UV light, so that the polymeric material of the film is cross-linked and the polymer electrolyte membrane is obtained

Correction to: New eco-friendly low-cost binders for Li-ion anodes

The article New eco-friendly low-cost binders for Li-ion anodes, written by D. Versaci, R. Nasi, U. Zubair, J. Amici, M. Sgroi, M. A. Dumitrescu, C. Francia, S. Bodoardo and N. Penazzi, was originally published electronically on the publisher's internet portal (currently SpringerLink)

DFTB+, a software package for efficient approximate density functional theory based atomistic simulations

DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods. Based on the DFTB framework, it additionally offers approximated versions of various DFT extensions including hybrid functionals, time dependent formalism for treating excited systems, electron transport using non-equilibrium Green's functions, and many more. DFTB+ can be used as a user-friendly standalone application in addition to being embedded into other software packages as a library or acting as a calculation-server accessed by socket communication. We give an overview of the recently developed capabilities of the DFTB+ code, demonstrating with a few use case examples, discuss the strengths and weaknesses of the various features, and also discuss on-going developments and possible future perspectives

Structural Interpretation of "Armate travi" in N-E Italy through the Historical Treatises

The study aims to clarify the geometrical configuration and the behaviour of a particular typology of wooden beams. Historically double framework wooden floors have covered wide rooms or loggias; frequently the principal beams were made up of more wooden elements assembled together to reach considerable length. The technology of «trave armata» allows to cover large spaces – up to 12/16 meters – by using small, shaped assembled and vertical nailed elements in order to obtain a single beam. This technology spread over a large area in northern Italy between XV and XVI centuries. There are a lot of examples in buildings (palaces, castles, loggias) along the Adige's path, in Trento, Verona, Mantova and Ferrara (Badalini and Dandria 2009), but also in the large area among Emilia and Lombardia and other singular cases in Firenze. Others examples of composite beams were studied in Provence (Bouticourt 2008) and some indications suggest an extention of this technology further the entire alpine arch. In addition the european historical treatises confirm that this method was internationally known. In spite of they are quite common, this kind of structures hasn't been investigate in a specific way, except for the F.E.M. analisys applied in Ferrara for reconstructing the distribution of stress end strains (Fabbri 2005), and it hasn't been elaborated an appropriate calculation procedure to verify the structure. The aim of this study is to connect together the geometrical and dimensional data come from the detailed surveys of most significant floors with the informations derived from treatises in order to comprehend the assembling procedure, the role of geometrical and static characteristics and to evaluate them

Planning low carbon urban-rural ecosystems: An integrated transport land-use model

As urbanization gradually modifies natural ecosystems and affects environmental sustainability, urban spatial planning can be used as a tool to address to Urban Metabolism and meet sustainable development targets. The concentration of people in urban areas makes these increasingly requiring for primary products and services as food and energy, and the fulfilment of such needs result in significant carbon emissions. The inclusion of spatial functions as agriculture and renewables in the urban planning can address to this environmental impact, but would require support-planning tools able to explore new land-use allocation strategies within an integrated urban-rural ecosystem. In this paper, we propose an optimization framework for the planning of low carbon urban-rural ecosystems that integrates transport and land-use planning and cope with urban metabolism, involving urban mobility, food transportation, energy supplies. This framework contributes to the literature as it formulates a network between urban, agricultural, energy, and carbon mitigation land-covers and optimizes the horizontal carbon fluxes within an integrated urban-rural environment. In order to minimize carbon emissions by mobility and resources (i.e. food) transportation, the framework aids identifying trade-offs between accessibility and density over the spatial distribution of resource-generating and resource-consuming land-covers. Proof of concept is provided with a realistic numerical example, propelled by real-world data from an Italian region. The land-use allocation solution makes the exemplifying urban-rural ecosystem behaving as carbon sink due to the established green areas and the configuration of the spatial uses. A sensitivity analysis is finally carried out to assess the impacts of mobility and resources transportation on the spatial urban-rural structure and associated carbon emissions. It comes out that the optimal urban configuration to mitigate carbon emissions from transportation integrates urban and rural uses and guarantees accessibility to several functions as cultivated areas, renewables and green covers, responsible to provide food, energy and air cleaning respectively to dwellers