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2020 - A model for renewable energy symbiosis networks in eco-industrial parks [Relazione in Atti di Convegno]
Butturi, Maria Angela; Sellitto, Miguel A:; Lolli, Francesco; Balugani, Elia; Neri, Alessandro

Renewable energy technologies integration within industrial districts can boost carbon emissions reduction in the industry sector. The eco-industrial parks model promotes the sustainable use of energy and the application of energy synergies and energy exchanges that can include renewable sources of energy. This paper presents an optimization methodology based on a multi-stakeholder perspective to evaluate energy symbiosis including the integration of renewable energy sources within the parks. The study results in three scenarios providing to managers of single firms and parks relevant information for supporting decision making regarding the economic sustainability and the environmental impacts of the energy synergies. The results show that the optimization of the collective point of view ensures more efficient management of the energy supplied by renewables as well as by firms that can provide an energy surplus.

2020 - Application of the quality function deployment approach to the optimization of an enterprise resource planning software [Relazione in Atti di Convegno]
Marinello, S.; Berte, S.; Lolli, F.; Butturi, M. A.

Enterprise Resource Planning (ERP) software are essential tools for those business activities that want to be competitive on the market: their use allows to manage all the economic and organizational aspects of a company, optimizing the use of resources. For this reason, the structure and functions of this software must be able to manage countless heterogeneous business aspects and, often, characteristic for each individual company. Therefore, during the design and the development phases it is necessary to analyze and understand the interests and needs of the end users, combining them with technical and market aspects. An approach capable of combining these aspects is the House of Quality (HoQ), a tool of Quality Function Deployment. It, applicable to new products or to the optimization of existing ones, allows to effectively identify and order the technical specifications and functions of the software (HOWs) by evaluating the most important requests of user customers (WHATs). This study describes the application of HoQ to the optimization of an ERP software, identifying the main critical elements in the existing configuration and co-designing a new version through the direct involvement of users, evaluating the importance of their needs.

2020 - Balancing of Manual Reconfigurable Assembly Systems with Learning and Forgetting Effects. [Relazione in Atti di Convegno]
Butturi, Maria Angela; Lolli, Francesco; Menini, Chiara

2020 - Barriers, drivers, and relationships in industrial symbiosis of a network of Brazilian manufacturing companies [Articolo su rivista]
Sellitto, Miguel Afonso; Murakami, Fábio Kazuhiro; Butturi, Maria Angela; Marinelli, Simona; Kadel, Jr. Nelson; Rimini, Bianca

2020 - Data on the environmental performance analysis of a dual-source heat pump system [Articolo su rivista]
Marinelli, S.; Butturi, M. A.; Lolli, F.; Rimini, B.; Gamberini, R.

This data article reports supplementary input and output data related to the research article “Environmental performance analysis of a dual-source heat pump system” on the life cycle assessment evaluation of an heat pump prototype, able to use alternatively the air and the ground as external heat sources. Primarily, the present article shows the life cycle inventory input data of the system under study and of the conventional air and ground heat pump systems, which were used for comparison. Secondly, complete numerical results are exposed, which are showed only graphically and in an aggregated form in the main article. Data include normalised and unaggregated environmental impacts of each investigated life cycle phase. The article also reports the complete results of the sensitivity analysis conducted using different assumptions on the energy mix and on the energy use.

2020 - Ecotoxicity of Plastics from Informal Waste Electric and Electronic Treatment and Recycling [Articolo su rivista]
Butturi, Maria Angela; Marinelli, Simona; Gamberini, Rita; Rimini, Bianca

Plastic materials account for about 20% of waste electrical and electronic equipment (WEEE). The recycling of this plastic fraction is a complex issue, heavily conditioned by the content of harmful additives, such as brominated flame retardants. Thus, the management and reprocessing of WEEE plastics pose environmental and human health concerns, mainly in developing countries, where informal recycling and disposal are practiced. The objective of this study was twofold. Firstly, it aimed to investigate some of the available options described in the literature for the re-use of WEEE plastic scraps in construction materials, a promising recycling route in the developing countries. Moreover, it presents an evaluation of the impact of these available end-of-life scenarios on the environment by means of the life cycle assessment (LCA) approach. In order to consider worker health and human and ecological risks, the LCA analysis focuses on ecotoxicity more than on climate change. The LCA evaluation confirmed that the plastic re-use in the construction sector has a lower toxicity impact on the environment and human health than common landfilling and incineration practices. It also shows that the unregulated handling and dismantling activities, as well as the re-use practices, contribute significantly to the impact of WEEE plastic treatments.

2020 - Empirical Evaluation of the Impact of Resilience and Sustainability on Firms’ Performance [Articolo su rivista]
Balugani, Elia; Butturi, Maria Angela; Chevers, Delroy; Parker, David; Rimini, Bianca

The concepts of resilience and sustainability appear multi-dimensional and correlated, depending on the context. Operational sustainability practices can enhance the resilience of a firm, and support its growth. This study aims at analyzing the impact of a sustainability strategy, measured by means of a sustainability maturity index (SMI), on the financial performance of a company. Since the SMI is strictly correlated to resilience capabilities, the performed analysis represents a first level integration of the sustainability and resilience indicators in a common framework. A data sample from 53 organizations was collected through structured interviews and analyzed to identify possible relationships between the SMI and the financial performance indexes. The analysis does not support commonly reported arguments: we show that profitability does not show a significant relationship with sustainable strategic intent. Interestingly, firm country of origin, size of the organization, and market focus, likewise, do not have a significant relationship with SMI. Arguably, multi-dimensional company performance, including both financial and non-financial measures, should be considered to assess the impact of sustainability practices. Moreover, further investigations are needed to capture firms’ nonfinancial indicators of performance that are related to sustainability and resilience, for building up a unified framework enabling trade-off analysis.

2020 - Environmental benefits of the industrial energy symbiosis approach integrating renewable energy sources [Relazione in Atti di Convegno]
Marinelli, S; Butturi, M. A.; Balugani, E.; Lolli, F.; Rimini, B.

Industry sector accounts for almost 40% of final energy demand and is responsible for one-fifth of global energy-related CO₂ emissions. A viable pathway to reduce the carbon footprint of the industry sector is represented by the industrial energy symbiosis, that promotes inter-firm energy exchanges and the sharing of energy-related resources. While a single firm comes across technical and financial barriers that often hamper the implementation of energy conservation projects, the cooperation between firms can enable energy saving measures and the use of renewable energy sources at industry level. Considering a case study involving an energy intensive industry, the study analyses the potential environmental benefits of the industrial energy symbiosis approach integrating renewable energy sources. The research suggests a methodology to design strategic energy symbiosis connections, advantageous for the involved firms, with the objective of reducing carbon emissions and economic costs. The methodology is based on the mathematical optimization through mixed integer linear programming. combined with the environmental analysis conducted with the life-cycle assessment method. The application of the methodology to the case study provides a scenario outlining all the potential energy flows, that are evaluated respect to the state-of-the-art (reference) scenario and alternative electrification strategies, showing the potential environmental benefits.

2020 - Environmental performance analysis of a dual- source heat pump system [Articolo su rivista]
Marinelli, S.; Lolli, F.; Butturi, Maria Angela; Rimini, B.; Gamberini, R.

Using all phases of a life cycle assessment (LCA), this paper analyses the environmental impact of a dualsource heat pump (DSHP) system that uses either the air or the ground as external heat sources. Data on the production were provided by the manufacturer of the heat pump prototype. The use phase was considered by evaluating the seasonal and annual energy performance of the system, using dynamic simulations. The system maintenance and end-of-life were modelled in accordance with the current regulations and statistical data in this sector. The Ecoinvent database was used as a reference for background data. The ReCiPe, CED and IPCC 100a impact methods were used to assess the environmental impact categories. The results were compared with those of conventional air and ground source heat pump systems. A sensitivity study on the influence of the energy in the use phase was carried out in terms of a variation in energy use and for different energy mixes, including photovoltaic energy. The results demonstrated the environmental validity of the technology in comparison with the two conventional heat pumps used for residential applications in different conditions. The results could be used by heat pump manufacturers to improve the design and performance of their products, by designers in the selection of thermal technologies, and by researchers involved in the study of similar emerging renewable energy technologies.

2020 - Evaluating the environmental benefit of energy symbiosis networks in ecoindustrial parks [Relazione in Atti di Convegno]
Marinelli, Simona; Butturi, Maria Angela; Rimini, Bianca; Gamberini, Rita; Marinello, Samuele

In order to evaluate the environmental benefits of energy industrial symbiosis networks with the inclusion of renewable technologies, a model that minimises greenhouse gases emissions has been developed. A validation of the model has been carried out comparing the results with those calculated with a life cycle assessment of a reference case. The study demonstrates that energy industrial symbiosis networks integrating renewable energy technologies have the potential to significantly reduce greenhouse gases emissions and suggests a methodology to optimise energetic symbiosis connections inside eco-industrial parks.

2020 - Logistic regression for criteria weight elicitation in PROMETHEE-based ranking methods [Relazione in Atti di Convegno]
Balugani, Elia; Lolli, Francesco; Butturi, Maria Angela; Ishizaka, Alessio; Afonso Sellitto, Miguel

For a PROMETHEE II method used to rank concurrent alternatives both preference functions and weights are required, and if the weights are unknown, they can be elicited by leveraging present or past partial rankings. If the known partial ranking is incorrect, the eliciting methods are ineffective. In this paper a logistic regression method for weight elicitation is proposed to tackle this scenario. An experiment is carried out to compare the logistic regression method performance against a state-of-the-art linear weight elicitation method, proving the validity of the proposed methodology.

2020 - The Geolocation of an Industrial Plant by Means of a Multi-Criteria Fuzzy Approach [Relazione in Atti di Convegno]
Butturi, M. A.; Lolli, F.; Filippi, D.

An innovative company should be ready to take advantage of all the opportunities offered by the market as well as to face the market challenges, and particularly to meet customers' needs. Thus, when compiling a business plan, the use of decision support tools can improve the presented solutions. This paper presents a method for the geolocation of a new industrial plant, to become competitive in the customer mind-set. An innovative project in the E-mobility sector of a company based in Europe concerned a partnership with a corporation and required a new plant located in the US. The problem of the geolocation is solved using a fuzzy analytic hierarchy process approach. Ten key factors that could potentially affect the location of a newcomer in the US have been selected and analyzed, and the State for the optimal location identified.

2020 - Urban-industrial symbiosis to support sustainable energy transition [Articolo su rivista]
Butturi, Maria Angela; Gamberini, Rita

Despite the growing interest in the field of urban–industrial symbiosis as well as in sustainable energy solutions at the city level, a research gap is recognized in terms of analyzing the advantages of energy symbiosis networks between industrial and urban areas integrating renewable energy systems. The urban–industrial symbiosis can support both urban transition toward sustainability and industrial green innovation through creating advantageous relationships in the framework of a common low-carbon strategy between industrial districts and neighboring urban areas. Urban–industrial symbiosis extends the concept of industrial symbiosis, a part of the industrial ecology field, to urban–industrial synergies. Taking advantage of the geographic proximity, it promotes the exchanges of waste, resources, and energy between urban and industrial areas, as well as the sharing of infrastructure. Thus, the paper aims at presenting an in-depth analysis of the main urban–industrial symbiosis schemes based on low-carbon energy flows between industries and cities, investigating the energy synergies potential. It introduces the concept and outline of sustainability-driven framework with the aim of modeling urban–industrial energy symbiosis networks integrating renewable energy sources from a multi-stakeholder point of view and supporting decision-making on the economic, environmental, and social sustainability of the energy synergies.

2019 - Cost-benefit evaluation of investment in natural gas distribution [Relazione in Atti di Convegno]
Balugani, Elia; Butturi, Maria Angela; Lolli, Francesco; Rimini, Bianca

Investment in the distribution of natural gas must be assessed by combining a technical analysis of the investment and an assessment of the social costs and benefits, to evaluate the impact of the project on social welfare in monetary terms. This paper describes how such an analysis can be conducted, by developing a methodology for the evaluation of investment in the distribution of natural gas. Once the net social benefit (NSB) of the investment has been evaluated, it is also important to assess the degree of reliability of such an estimate. This assessment can be conducted through two types of tests: sensitivity analysis and risk analysis. The critical variables are identified in sensitivity analysis as those that have a significant impact on the predicted outcome when they change. To address any uncertainties in the critical variables, a risk analysis quantifies the probability that the NSB is less than that estimated when using modal values for the critical variables. This type of analysis, combined with a technical evaluation, can be effectively used to assess the social consequences of an investment.

2019 - KnowRISK on seismic risk communication: The set-up of a participatory strategy- Italy case study [Capitolo/Saggio]
Musacchio, G.; Falsaperla, S.; Solarino, S.; Piangiamore, G. L.; Crescimbene, M.; Pino, N. A.; Eva, E.; Reitano, D.; Manzoli, F.; Fabbri, M.; Butturi, M.; Accardo, M.

KnowRISK (Know your city, Reduce seISmic risK through non-structural elements) is a European project that addresses prevention measures to reduce non-structural damage caused by earthquakes. It is built on risk communication and takes action on pilot areas of the three participating countries: Portugal, Iceland, and Italy. The setting up of risk communication strategies in the project stands on the understanding local communities fragility, on their direct engagement, and on a holistic approach to vulnerability. The level of relevance of seismic compared to other hazards, the understanding, the memory of past disasters are indicators that affect the way a risk is perceived and preventive measures are taken. Similarly, the level of education, wealth, exposure to other, social, risks are aggravation parameters in risk computation to be accounted for when we communicate risk. Strategies for risk communication in KnowRISK rely on schools and citizen’s engagement, citizen’s science activities, tools for raising awareness.

2019 - On the elicitation of criteria weights in PROMETHEE-based ranking methods for a mobile application [Articolo su rivista]
Lolli, Francesco; Balugani, Elia; Ishizaka, Alessio; Gamberini, Rita; Butturi, Maria Angela; Marinello, Samuele; Rimini, Bianca

Today, almost everybody has a smartphone and applications have been developed to help users to take decisions (e.g. which hotel to choose, which museum to visit, etc). In order to improve the recommendations of the mobile application, it is crucial to elicit the preference structures of the user. As problems are often based on several criteria, multicriteria decision aiding methods are most adequate in these cases, and past works have proposed indirect eliciting approaches for multicriteria decision aiding methods. However, they often do not aim of reducing as much as possible the cognitive efforts required by the user. This is prerequisite of mobile applications as they are used by everybody. In this work, the weights to assign to the evaluation criteria in a PROMETHEE-based ranking approach are unknown, and therefore must be elicited indirectly either from a partial ranking provided by the user or from the selection of his/her most preferred alternative into a subset of reference alternatives. In the latter case, the cognitive effort required by the decision-maker is minimal. Starting from a linear optimisation model aimed at searching for the most discriminating vector of weights, three quadratic variants are proposed subsequently to overcome the issues arising from the linear model. An iterative quadratic optimisation model is proposed to fit the real setting in which the application should operate, where the eliciting procedure must be launched iteratively and converge over time to the vector of weights, which are the weights that the user implicitly assigns to the evaluation criteria. Finally, three experiments are performed to confirm the effectiveness and the differences between the proposed models.

2019 - Renewable energy in eco-industrial parks and urban-industrial symbiosis: A literature review and a conceptual synthesis [Articolo su rivista]
Butturi, M. A.; Lolli, F.; Sellitto, M. A.; Balugani, E.; Gamberini, R.; Rimini, B.

Replacing fossil fuels with renewable energy sources is considered as an effective means to reduce carbon emissions at the industrial level and it is often supported by local authorities. However, individual firms still encounter technical and financial barriers that hinder the installation of renewables. The eco-industrial park approach aims to create synergies among firms thereby enabling them to share and efficiently use natural and economic resources. It also provides a suitable model to encourage the use of renewable energy sources in the industry sector. Synergies among eco-industrial parks and the adjacent urban areas can lead to the development of optimized energy production plants, so that the excess energy is available to cover some of the energy demands of nearby towns. This study thus provides an overview of the scientific literature on energy synergies within eco-industrial parks, which facilitate the uptake of renewable energy sources at the industrial level, potentially creating urban-industrial energy symbiosis. The literature analysis was conducted by arranging the energy-related content into thematic categories, aimed at exploring energy symbiosis options within eco-industrial parks. It focuses on the urban-industrial energy symbiosis solutions, in terms of design and optimization models, technologies used and organizational strategies. The study highlights four main pathways to implement energy synergies, and demonstrates viable solutions to improve renewable energy sources uptake at the industrial level. A number of research gaps are also identified, revealing that the energy symbiosis networks between industrial and urban areas integrating renewable energy systems, are under-investigated.

2018 - Distributed renewable energy generation: a critical review based on the three pillars of sustainability [Relazione in Atti di Convegno]
Butturi, Maria Angela; Lolli, Francesco; Balugani, Elia; Gamberini, Rita; Rimini, Bianca

Reducing emissions responsible for the climate change is recognized as a strategic goal at European and global level. A higher deployment of renewable energy sources is considered as essential for a low-carbon transition, towards a more sustainable energy system. The 2030 Framework for Climate and Energy sets out the European Union target for 2030 of at least 27% for the share of renewable energy consumption. A high share of renewables requires a new flexible and integrated electricity system to ensure grid stability and match supply and demand. The advances in technologies for renewable electricity and heating production, efficient storage solutions, and advanced ICT allow flexible electrical infrastructures: distributed renewable energy generation is now widely recognized as the main pathway towards an effective integration of discontinuous sources into the energy system. The discussion on renewable energy sources introduction in the energy system has long been focused on technical, economic and policy issues, but the transition to a distributed renewable energy generation approach demands a change of perspective, considering a multi-sectoral sustainability view and the need for multi-stakeholder action. Purpose of this research is reviewing the more recent scientific papers on the distributed renewable energy generation approach, focusing on how all the three key sustainability dimensions, environmental, economic and social, are evaluated and managed in a multi-criteria perspective. The sustainability indicators suggested in literature are classified and discussed to build up an up-to-date and comprehensive set of sustainability related criteria, suitable for future research applications and for supporting decision making processes.

2015 - Development of a high/low concentration photovoltaic module with dichroic spectrum splitting [Articolo su rivista]
Antonini, A.; Butturi, M. A.; Zurru, P.; Norton, M.; Parretta, A.

A concentrating photovoltaic module design incorporating a spatial spectral splitting approach with dichroic mirrors is presented. The advantages of this technology are reported, as well as a short description of the design evolution process. The experimental results are summarised, highlighting possible improvements through the use of different production processes and components. Materials, design and assembly procedures are taken into account, keeping in mind the fundamental constrains of cost and reliability of the final product. Finally, the possibilities for market exploitation of this technology in the current photovoltaic landscape are analysed.

2015 - Development of a mirror-based LCPV module and test results [Articolo su rivista]
Antonini, A.; Butturi, M. A.; Zurru, P.

The design and the technical features of a low concentration photovoltaic module based on silicon solar cells are here presented, reporting manufacturing topics and results of experimental tests. The product here described has been developed, taking into account costs, efficiency, reliability, and investments required for its industrial production and for its commercial exploitationThe design of a specific low concentration photovoltaic module is described here, with a report of the results of the first experimental tests of its industrial version. The product is a 20× reflective concentrating photovoltaic module based on silicon solar cells. The optics were designed to mount these modules on 2-axis trackers with angular pointing accuracy of up to about ±4° without significant power loss. The high angular acceptance of the non-imaging optics permits the collection of a high fraction of the circumsolar light impinging on the module's frontal aperture, providing high direct normal irradiance efficiency in real operative conditions. Many technical features of the product are described here, in which features are the result of 5 years of product development in order to improve performance, reliability and cost issues.

2012 - Optical simulation of Rondine® PV solar concentrators by two inverse characterization methods [Articolo su rivista]
Parretta, A.; Aldegheri, F.; Antonini, A.; Butturi, M.; Zurru, P.

In this paper we describe two optical characterization methods applied to photovoltaic solar concentrators. Both methods are of the 'inverse' type, where the light source is applied in place of the receiver in order to reverse the path of light inside the concentrator. The first method is the 'inverse illumination method', already known in the literature, whereas the second one is a method obtained by modifying the 'inverse luminescence method', operating with electroluminescent light. Both methods use ideal Lambertian sources for producing the inverse light and can be applied to any type of solar concentrator (photovoltaic or thermodynamic). The optical simulations show their equivalence in obtaining the angular distribution of the transmission efficiency function of Rondine® PV concentrators, but the original inverse illumination method requires a simpler configuration and significantly lower simulation times. © 2012 IOP Publishing Ltd.

2011 - Optimization of point focus and mirror based spectrum splitting CPV systems: results from tha Apollon Project [Abstract in Atti di Convegno]
Timò, Gianluca; Minuto, Alessandro; Morabito, Paolo; Martinelli, Alessio; Chemelli, Cristina; Sagnes, Isabelle; Jakomin, Roberto; Beaudoin, Gregoire; Schineller, Bernd; Heuken, Michael; Sturm, Matthias; Butturi, Maria Angela; Antonini, Andrea; Zurru, Paolo; Noack, Michael; Padovani, Sara; di Vora, Igor; Borshchov, Slava; Kenny, Robert; Aitasalo, Tuomas; Roca, Francesco; Graditi, Giorgio; Cancro, Carmine; Pellegrino, Michele; Privato, Carlo; Medina, Eduardo; Heasman, Keith; de Wild-Scholten, Mariska; Olson, Carol; Aleo, Francesco; Luisa Lo Trovato, Maria; Vincenzi, Donato; Guidi, Vincenzo; Georghiou, George E.; Norton, Matthew

An overview of the achievements accomplished in the first phase of the APOLLON project, related to the optimisation of point focus (PF) and mirror based spectra splitting systems (MBS3) is presented as well as some preliminary results on the proposed innovative Concentrating Photovotaic (CPV) technologies (intelligent CPV modules).

2009 - Rondine PV concentrators: Field results and progresses [Relazione in Atti di Convegno]
Antonini, A.; Butturi, M. A.; Di Benedetto, P.; Uderzo, D.; Zurru, P.; Milan, E.; Parretta, A.; Baggio, N.

In this work the experimental results of two pilot installations of 3.8 kWp and 4.9 kWp of Rondine PV concentrators installed in Italy are presented. These concentrating modules have a medium concentration level (25×) and employ silicon solar cells. The non-imaging optics of the concentrator allows for larger angular acceptance respect to many CPV modules, giving us the possibility to employ trackers for standard PV modules. The effect of soiling in these first installations is evaluated as well as their working conditions in different weather situations.

2009 - Rondine® PV concentrators: Field results and developments [Articolo su rivista]
Antonini, A.; Butturi, M. A.; Di Benedetto, P.; Uderzo, D.; Zurru, P.; Milan, E.; Stefancich, M.; Armani, M.; Parretta, A.; Baggio, N.

In this work the experimental results of a new PV concentrator (named Rondine®) are presented. This concentrating module has a medium concentration level (∼25X) and employs silicon solar cells. The tests have been carried out in Italy and the energy production of a prototype module is compared with that produced from a tracking flat plate crystalline PV panel. The non-imaging optics of the concentrator allows for larger angular acceptance with respect to many solar concentrators, giving us the possibility to employ trackers for standard PV modules. The first results of complete systems of 3-9 and 4-8 kW of peak power installed in summer 2008 are presented here. Copyright © 2009 John Wiley & Sons, Ltd.

2007 - Silicon micromachining techniques as a tool to fabricate channeling-based devices [Relazione in Atti di Convegno]
Antonini, A.; Butturi, M.; Guidi, V.; Martinelli, G.; Mazzolari, A.; Milan, E.

During the last years, because of the low cost, high crystalline perfection and sound knowledge on the handling, the use of bent silicon crystals for applications in accelerators has been intensively investigated. In particular, great attention has been paid towards improving extraction efficiency by the methods used to realize the crystals. For example, 70 GeV protons were extracted from the beam accelerator in Protvino with silicon crystal, obtaining a channeling efficiency close to 85%. The key reason for this successful operation was the use of very short bent crystals. Realization of the short bent crystal devices, as a crystalline undulator, can be difficult by traditional mechanical techniques; a possible alternative method could be the deposition of a high residual stress film onto a Si wafer. We have studied and tested two alternative methods to achieve a uniform curvature of silicon wafers: deposition of both silicon nitride films and thick aluminium films.

2004 - Aqueous and alcoholic syntheses of tungsten trioxide powders for NO2 detection [Articolo su rivista]
Guidi, V.; Blo, M.; Butturi, M. A.; Carotta, M. C.; Galliera, S.; Giberti, A.; Malagu, C.; Martinelli, G.; Piga, M.; Sacerdoti, M.; Vendemiati, B.

Different synthetical routes involving several solvents for obtaining WO3powders, suitable for gas sensing have been studied. Aqueous and alcoholic solvents proved to be the most promising media to grow nanometric particles. Among these, a modified sol-gel route that involves ethanol and a di-chetone, highlighted a more homogeneous grain-size distribution. The structure and morphology evolution of pure WO3powders with time and annealing temperature have been studied. The study of the energy barrier and conductance versus temperature allows to understand the reason for the high response of WO3to oxidising gases and its lack of sensitivity to reducing agents. Films of WO3responded to NO2, sensing as low a gas concentration as 200ppb. © 2003 Elsevier B.V. All rights reserved.

2004 - Effects of thermal annealing on the structural properties of sputtered W-Si-N diffusion barriers [Articolo su rivista]
Vomiero, A.; Marchi, Eb; Frabboni, Stefano; Quaranta, A.; Della Mea, G.; Mariotto, G.; Felisari, L.; Butturi, M.

W-Si-N thin films were deposited via rf-magnetron sputtering from a W5Si3 target in Ar/N-2 reactive gas mixtures over a large range of compositions, obtained by varying the partial flow of nitrogen within the reaction chamber. The samples of each set were then thermally annealed in vacuum at different temperatures up to 980 degreesC. Film composition was determined by Rutherford backscattering spectrometry (RBS), surface film morphology by scanning electron microscopy (SEM), micro-structure by transmission electron microscopy (TEM), vibrational properties by FT-IR absorption and Raman scattering spectroscopy, and electrical resistivity by four-point probe measurements. Independently of the deposition conditions, all the as-deposited films have an amorphous structure, while their composition varies, showing an increase of Si/W ratio from 0.1 up to 0.55 when the nitrogen concentration in the films increases from 0 to 60 at%. Thermal treatments in vacuum induce an important loss of nitrogen in the nitrogen-rich samples, especially at temperatures higher than 600 degreesC. Samples with high nitrogen content preserve their amorphous structure even at the highest annealing temperature, despite the chemical bonding ordering observed by means of FTIR measurements. Raman spectroscopy of as-deposited films rich in nitrogen suggests the presence of an important amorphous silicon nitride component, but fails to detect any structural rearrangement either within the composite matrix of film or within silicon nitride component. Segregation of metallic tungsten was detected by TEM in the annealed sample with lowest nitrogen content (W58Si21N21). Finally, the resistivity of the films increases with the N content, while the loss of nitrogen accompanies the decrease of resistivity especially of samples with high nitrogen content.

2002 - Contact shadowing losses reduction by fine line screen printing [Relazione in Atti di Convegno]
Butturi, M. A.; Stefancich, M.; Vincenzi, D.; Martinelli, G.; Pirozzi, L.; Arabito, G.; Mizzi, M.; Mangiapane, P.

Aim of this work is to transfer high efficiency concepts to large-scale crystalline silicon solar cell production, which is based on screen printing technology. The achievable cell efficiency obtainable by this technique is strongly affected by the limitation due to the contact shadowing losses necessary for reaching high Fill Factor values; indeed highest the FF, highest the surface coverage. An appealing way to overcome this limitation is to join screen printing to buried contact technology to get high aspect ratio grid pattern and, at the same time, a high FF value. Moreover this technology allows to easily define a selective emitter. Keeping to this purpose high resolution polymer screens or stencils with variable thickness have been tested. Both this steps have been obtained by adjusting the conventional screen printing process.

2002 - Gas sensing through thick film technology [Articolo su rivista]
Guidi, V.; Butturi, M. A.; Carotta, M. C.; Cavicchi, B.; Ferroni, M.; Malagu, C.; Martinelli, G.; Vincenzi, D.; Sacerdoti, M.; Zen, M.

We report in our research on semiconductor-based sensing layers deposited via thick-film technique. Particular focus was devoted to achieve nanosized films through proper processing and to study their morphological and structural features. Nanosized powders were prepared by sol-gel method or laser-assisted spray pyrolysis. We also considered some techniques to maintain the stability of a nanostructure for long-term usage of the sensing layers. We detailed the preparation of screen printing pastes suitable for gas sensing application. Implementation of the sensing film on a low-power-consumption micromachined hotplate has also been addressed. The performance of such devices is presented and compared to that of conventional units. © 2002 Elsevier Science B.V. All rights reserved.

2002 - Micro-gas-sensor with conducting polymers [Articolo su rivista]
Guidi, V.; Butturi, M. A.; Carotta, M. C.; Cavicchi, B.; Ferroni, M.; Malagu, C.; Martinelli, G.; Vincenzi, D.; Sacerdoti, M.; Zen, M.

A study on semiconductor-based sensing layers deposited via thick-film method was carried out, with emphasis on achieving nanosized films through proper processing and studying their morphological and structural features. Screen-printing is a valuable method for deposition of sensing thick-films over either conventional substrates or recently-developed micromachined hotplates. The preparation of a suitable material for deposition was highlighted through titania as a practical example. Nanostructured titania powders could be stabilized for long-term operation by doping. As an example of the electrical performance, the response of the sensor to CH4 was shown. The response of the sensor towards different concentrations of CO, NO2, and CH4 showed that it was mostly sensitive to NO2 within 0-0.1 ppm, i.e., for environmental monitoring. The integration of the thick-film method with Si-micromachining processing opens up prospects for large-scale production of hybrid devices featuring low power consumption and reduced dimensions.

2001 - Development of a low-power thick-film gas sensor deposited by screen-printing technique onto a micromachined hotplate [Articolo su rivista]
Vincenzi, D.; Butturi, M. A.; Guidi, V.; Carotta M., C; Martinelli, G.; Guarnieri, V.; Brida, S.; Margesin, B.; Giacomozzi, F.; Zen, M.; Pignatel G., U; Vasiliev A., A; Pisliakov A., V

We report on the design, implementation and characterisation of a thick-film gas sensor deposited for the first time by screen-printing technique onto a micromachined hotplate, the microheater maintains a film temperature as high as 400°C with <30mW of input power. The microheater consists of a dielectric stacked membrane equipped with embedded polysilicon resistors acting as heating element as well as temperature sensing elements. Extensive finite-element computer simulations were carried out during the design step to optimise the radial temperature gradient up to 1200°C/mm. A newly developed scheme for temperature measurement was adopted for on-line adjustment of the film temperature through a conventional low-power proportional integral (PI) regulator. Deposition of sensing layers based on semiconductor oxides, such as SnO2 was achieved by computer-aided screen-printing. The films were then fired through the microheater itself to guarantee thermodynamic stability for long time exploitation. The response of the device to CO, CH4 and NO2 at concentrations typical for indoor and outdoor applications was recorded by measuring the film resistance through ultra high impedance CMOS circuit. © 2001 Elsevier Science B.V.

2001 - Low-power thick-film gas sensor obtained by a combination of screen printing and micromachining techniques [Articolo su rivista]
Vincenzi, D.; Butturi, M. A.; Stefancich, M.; Malagu, C.; Guidi, V.; Carotta M., C; Martinelli, G.; Guarnieri, V.; Brida, S.; Margesin, B.; Giacomozzi, F.; Zen, M.; Vasiliev A., A; Pisliakov A., V

A novel prototype of low-power thick-film gas sensor deposited by screen-printing onto a micromachined hotplate is presented. The micro-heater is designed to maintain a film temperature of 400°C with less than 30 mW of input power. The fabrication process involves a combination of standard, VLSI-compatible, micromachining procedures and computer-aided screen-printing. A dielectric membrane of Si3N4 and SiO2 has been obtained with an embedded poly-Si resistor acting as a heating element. The bonding pad and contacts have been realised by a Ti/TiN/Cr/Au structure and the sensing film has been deposited by a screen-printing technique. Here follows a characterisation of a device, based on SnO2 sensing film, at working conditions together with the response curve for CH4 and NO2. We will also address some important improvements to the micro-hotplate structure, which leads to an increased flexibility of the device. © 2001 Elsevier Science B.V.

2001 - Mechanical effects of chemical etchings on monocrystalline silicon for photovoltaic use [Articolo su rivista]
Stefancich, M.; Butturi, M.; Vincenzi, D.; Martinelli, G.

The mechanical effects of two etching treatments commonly applied on silicon wafers for the PV industry, are considered. The failure characteristics of this material under concentrated load are shown. In both cases, the maximum elongation and sustainable load of the etched wafers were measured to be higher than those of the original sample. The employed experimental procedure and results are presented here and a statistical data analysis substantiates the results observed. An attempt of explanation for this effect is offered based on the removal of a shallow highly defective layer induced by the etching of the material. © 2001 Elsevier Science B.V.

2000 - Gas-sensing device implemented on a micromachined membrane: A combination of thick-film and very large scale integrated technologies [Articolo su rivista]
Vincenzi, D.; Butturi, M. A.; Guidi, V.; Carotta, M. C.; Martinelli, G.; Guarnieri, V.; Brida, S.; Margesin, B.; Giacomozzi, F.; Zen, M.; Giusti, D.; Soncini, G.; Vasiliev, A. A.; Pisliakov, A. V.

A low-consumption thick-film gas sensor based on micromachining methods has been designed, fabricated, and tested. It consists of a dielectric stacked membrane micromachined from bulk silicon, with an embedded polysilicon resistor as a heater, over which the gas-sensing layer was deposited by computer-aided screen printing. Power consumption as low as 30 mW turned out to be sufficient to react 400 °C for the sensing film. Measured electrothermal characteristics are in good agreement with the outcomes of 3D finite element simulations.

2000 - Thick film microsensors based on nanosized titania sol-gel powder [Articolo su rivista]
Carotta, M. C.; Butturi, M. A.; Martinelli, G.; Di Vona, M. L.; Licoccia, S.; Traversa, E.

Thick films of nanostructured TiO2 and tantalum-doped TiO2 have been fabricated by screen-printing technology starting from pure titania and tantalum-doped titania powders prepared by sol-gel method. The titania powders, obtained via sol gel, show crystalline anatase structure and the particles are homogeneous and nanosized (30÷50 nm). Two series of films each one composed by pure and Ta-doped titania samples have been obtained by firing the pastes in air atmosphere at the temperatures of 650 °C and 850 °C, respectively. SEM observations and electrical characterizations showed that the firing temperature strongly influences the nanostructure and the gas response of the pure titania samples. The addition of tantalum inhibits the grain sintering at the higher temperature. Moreover the electrical data show that the tantalum addition (10 at.%) does not affect the conductance of the films in air while significantly enhances the response towards CO and leaves almost unaltered or enhances its ability to sense NO2 depending on the thermal treatments.

1997 - Effects of ageing on porous silicon photoluminescence: correlation with FTIR and UV-VIS spectra [Articolo su rivista]
Butturi, M. A.; Carotta, M. C.; Martinelli, G.; Passari, L.; Youssef, G. M.; Chiorino, A.; Ghiotti, G.

An analysis about the change of photoluminescence (PL) intensity during ageing in porous silicon (p-Si) at room temperature (RT) is reported. PL measurements have been correlated to Fourier transform infrared spectrometry (FTIR), UV-Vis reflectance spectra (RS) and transmission electron microscopy (TEM) with the aim of clarifying the basic mechanism of the luminescence intensity variation. After six months of ageing we observed a value of the PL intensity approximately 200 times greater than at beginning together with a blue-shift of 50 nm. The FTIR experiments evidenced that an oxygen passivation effect associated to the quantum confinement model allows to justify the observed behaviour under ageing; moreover the absorption edge of about 2 eV determined by the reflectance measurements corresponds to the high energy tail of the PL spectra. TEM images are also in agreement with the shift of the gap and with the wire shrinkage due to the SiO2layer observed by IR spectra. Copyright © 1996 Elsevier Science Ltd.

1997 - Microstructural evolution of nanosized LaFeO3powders from the thermal decomposition of a cyano-complex for thick film gas sensors [Articolo su rivista]
Carotta, M. C.; Butturi, M. A.; Martinelli, G.; Sadaoka, Y.; Nunziante, P.; Traversa, E.

Nanosized, single-phase perovskite-type LaFeO3powders are prepared by the thermal decomposition at 600°C of a hexacyanocomplex, La[Fe(CN)6].5H2O. The formation of LaFeO3and its microstructural evolution with the temperature have been studied by simultaneous thermogravimetric and differential thermal analysis (TG/DTA), x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). LaFeO3is formed by the decomposition of the complex with a peculiar morphology, consisting of nanosized particles in soft agglomerates with the same size and shape of the complex grains. The nanosized particles are free of pores, making the powders suitable for application in thick film fabrication, after disruption of the agglomerates, for their use as active elements for gas sensors. Preliminary experiences are encouraging the use of this sensor for NO2detection in the real environment. © 1997 Elsevier Science S.A.

1996 - Comparison between normal and reverse thin crystalline silicon solar cells [Articolo su rivista]
Benati, A.; Butturi, M. A.; Capperdoni, C.; Carotta, M. C.; Martinelli, G.; Merli, M.; Passari, L.; Sartori, G.; Van Steenwinkel, R.; Youssef, G. M.

The newly developed ingot growing techniques, as the three-grain and the columnar multigrain ingot processes, are now offering the possibility of slicing thinner wafers (≤ 100 μm). In this paper we present the results obtained on p type large area (≥ 100 cm2) and 100 μm thick wafers by using both conventional and reverse cell manufacturing technologies. The conventional cells are provided with aluminium or boron BSF plus screen-printed silver mirror or a silver-aluminium net; the reverse cells have a FSF and the deep back junction completely covered by a screen-printed or CVD silver layer. The constructing parameters have been chosen on the base of one and two dimensions modeling and both raw material and devices have been completely characterized. This work shows that very thin wafers do not introduce serious problems for the conventional manufacturing of solar cells. The efficiencies of the normal and of the reverse cells are found to be comparable and are of the same order than those of thicker cells, however at a significant lower cost. The main obtained result has to be related to the demonstration of a cell manufacturing feasibility starting from very thin wafers.

1996 - Electrical properties of silver impurities and their annealing behaviour in p-type Fz silicon [Articolo su rivista]
Adegboyega, G. A.; Passari, L.; Butturi, M. A.; Poggi, A.; Suzi, E.

The electrical activity of silver as well as its annealing properties in 10 Ω cm p-type Fz silicon substrate are studied by means of the four-point probe and minority carrier lifetime measurements. Silver atom concentration in the range 1014to 1015cm-3consistently showed a donor type behaviour in the material and its presence led to a reduction of up to two orders of magnitude in the lifetime of minority carriers by the formation of deep-level traps. Isochronal annealing of silver contaminated specimens showed some gettering of the Ag impurities with resulting temperature dependent changes in the resistivity as well as the minority carrier lifetime values. Analysis of our results shows that a large fraction of the silver impurity atoms present forms the deep level defects and both the deep- and donor-levels appear to originate from the same source. © Les Éditions de Physique 1996.