A novel approach to design sustainable fiber reinforced materials from renewable sources: mathematical modeling for the evaluation of the effect of fiber content on biocomposite properties

Abstract The paper reports a sustainable, fast and efficient methodology to treat natural hemp fibers (HF) using a mechanochemical approach. Mechanical milling was used to carry out an alkaline attack on HFs for 30 minutes at ambient temperature. Composites HF/pectins were prepared by varying the fiber weight fraction (3%; 7.5%; 10%; 20% w/w by weight). The improvement in thermal degradation, mechanical and barrier properties to water vapor was correlated with the fiber volume fraction and mainly due to the improved fiber-matrix adhesion. The fibers-matrix interaction was then evaluated by analyzing and modeling the mechanical properties using several mathematical models: a modified Nielsen and Pukanszky and Smith models. Sorption isotherms to water vapor were analyzed through a modified Guggenheim, Anderson, de Boer (GAB) model where a new parameter, α, was introduced to consider the heterogeneity of the system. Finally, a modified Burgemman model was used to fit the experimental data and support the improvement in water diffusion with fiber loading

Interoperability challenges for ICT-enabled governance: towards a pan-European conceptual framework

In the European academic and institutional debate, interoperability is predominantly seen as a means to enable public administrations to collaborate within Members State and across borders. The article presents a conceptual framework for ICT-enabled governance and analyses the role of interoperability in this regard. The article makes a specific reference to the exploratory research project carried out by the Information Society Unit of the Institute for Prospective Technological Studies (IPTS) of the European Commission¿s Joint Research Centre on emerging ICT-enabled governance models in EU cities (EXPGOV). The aim of this project is to study the interplay between ICTs and governance processes at city level and formulate an interdisciplinary framework to assess the various dynamics emerging from the application of ICT-enabled service innovations in European cities. In this regard, the conceptual framework proposed in this article results from an action research perspective and investigation of e-governance experiences carried out in Europe. It aims to elicit the main value drivers that should orient how interoperable systems are implemented, considering the reciprocal influences that occur between these systems and different governance models in their specific context

From Public Value to Social Value of Digital Government: Co-Creation and Social Innovation in European Union Initiatives

This paper discusses the development of key features in European Union policy and service redesign, based on social innovative practices where co-creation and the related phenomenon of digital social innovation have a high potential impact. The idea underneath this claim is that information and communication technologies are becoming increasingly pervasive in the design, development and delivery of social innovation and co-creation initiatives which should not be limited to service delivery, rather serve as the driver for opening-up governance systems and change the way public organizations are structured and policy designed and implemented. Consequently, the paper discusses the key elements identified for setting up open and collaborative governance systems, while, taking stock from the analysis of policy experiences and practices funded by the European Commission, an overview of main drivers and barriers are presented. The paper concludes outlining recommendations for future research, as well as implications and possible directions for policy

Coaxial electrospun membranes of poly(ε-caprolactone)/poly(lactic acid) with reverse core-shell structures loaded with curcumin as tunable drug delivery systems

AbstractNano fibrous membranes core‐shell of poly(lactic acid) (PLA) and poly(ε‐caprolactone) (PCL), encapsulating 1 wt% of curcumin, are fabricated by coaxial electrospinning technique. Morphology and physical properties, as well as the release of curcumin, are studied and compared with neat PLA and PCL individually spinned. Morphological analysis shows for all the samples the obtainment of fiber oriented in random way, without defect and with a narrow distribution of the fiber dimensions (344 nm for PCL fibers and 450 nm for PLA fibers). Mechanical performances and barrier properties are evaluated on all membranes and found to be dependent on the fibers' composition and morphology. Water contact angle for all membranes is found higher than 90° (from 103° for PLA‐Curc to 128° for PCL‐Curc), expected since the hydrophobic behavior of the micro/nano electrospun morphology. The curcumin release from the coaxial fibers, modeled with a modified Weibull equation, shows the possibility of a fine tuning of drug release (up to 15 days) for the produced materials, depending on the required application

Valorization of tomato processing residues through the production of active bio-composites for packaging applications

The present work reports a study aimed at investigating the recovery and the upgrade of tomato processing residues through the preparation of innovative green composites based on tomato peels (TPs) and natural halloysite nanotubes (HNTs) loaded with carvacrol, as a natural antibacterial agent. The loading of carvacrol into HNTs was successfully achieved through a simple procedure that does not involve any chemical modifications of HNTs. Composite films with different amount of HNTs (i.e., 2.5, 5, 10, 20%wt) were prepared using mechanical milling in presence of water, followed by solvent casting method. The structural organization and the main physical properties of the obtained bio-based active composites have been deeply investigated. In particular, thermal and mechanical properties along with the films' interaction with water vapor were assessed and then correlated to the filler loading. Results show that the thermal behaviour of bio-composites improves with the filler loading. Conversely, the mechanical properties get worse, especially at higher loading, due to the poor interaction between HNTs and matrix. The presence of hydrophilic HNTs was found to not dramatically increase the degree of hydrophilicity of the of the materials, most likely due to the presence of hydrophobic carvacrol that acts as an hydrophobic coating for HNTs. The release of carvacrol was also analyzed. Results show that the obtained composites exhibit a long-term release of the antimicrobial agent, which suggests them to be promising candidate materials for food packaging application

Green functionalization of biochar via mechanochemical approach

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Quercetin-Loaded Polycaprolactone-Polyvinylpyrrolidone Electrospun Membranes for Health Application: Design, Characterization, Modeling and Cytotoxicity Studies

Fibrous membranes of polycaprolactone (PCL)-polyvinylpyrrolidone (PVP) encapsulating 15% wt of quercetin are fabricated by a uniaxial electrospinning technique. Morphological analysis of the electrospun systems proved the fabrication of micrometric fibers (1.58 µm for PCL/PVP and 2.34 µm for quercetin-loaded membrane). The liquid retention degree of the electrospun membranes is evaluated by testing four different liquid media. The contact angle estimation is performed by testing three liquids: phosphate buffer solution, basic solution (pH = 13) and acidic solution (pH = 3), showing high hydrophobicity degree (contact angles > 90°) in all cases. The release of quercetin from the nanofibers in PBS (phosphate buffer solution) and pH = 3 medium, modeled through different models, shows the possibility of a fine tuning of drug release (up to 7 days) for the produced materials. The release profiles attained a plateau regime after roughly 50 h up to 82% and 71% for PBS and pH = 3 media, respectively. Then, since quercetin is known to undergo photooxidation upon UV radiation, release tests after different UV treatment times are carried out and compared with the untreated membrane, demonstrating that the release of the active drug changes from 82% for no-irradiated sample up to 57% after 10 h of UV exposure. The biology activity of released quercetin is evaluated on two human cell lines. The reported results demonstrate the ability of the quercetin-loaded membranes to reduce cell viability of human cell lines in two different conditions: direct contact between cells and quercetin-loaded membranes and cells treatment with culture medium previously conditioned with quercetin-loaded membranes. Therefore, the reported preliminary data confirm the possibility of applying the electrospun quercetin-loaded PCL-PVP membranes for health applications

Fabrication of Novel Bio-Composites Based on Rice Milk for the Delivery of Capsaicinoids as Green Herbicides against Cynodon dactylon Weed

In this paper, rice milk-based beads were fabricated through gelation in a calcium chloride solution. Green extraction of chili pepper in water/ethanol was conducted in order to obtain powder extract (PE) rich in apigenin C-pentosyl-C-hexoside, capsaicin, and dihydrocapsaicin. The effect of capsaicinoids loading on beads’ properties was evaluated in terms of morphological and physical properties. Swelling phenomena and diameter variation of beads were studied as a function of time proving correspondence with the PE amount. The effect of ionic strength on bead swelling was considered. Kinetic studies of PE release were conducted to investigate the release profiles, which were modeled through a modified Baker and Lonsdale model by considering the change in mean diameter over time. The effect of PE loading was then correlated to the growth of Cynodon dactylon weed through in vivo tests. The results corroborate the performances of the encapsulated PE to be used as natural and green herbicide release systems able to inhibit the growth and the proliferation of weeds

Managing e-Governance: a framework for analysis and planning

The purpose of this chapter is to present and discuss the application of an analytical framework for managing digital innovation initiatives in the public sector. The chapter positions e-Government and digital innovation initiatives in the public sector within the broader framework of e-Governance (i.e. the governance with and of ICT) (Misuraca, 2007). Taking these issues into account the chapter first discusses the conceptual framework at the basis of the analysis, proposing a higher order conceptualization of the relationship between e-Governance and its underpinning value drivers of performance, openness, and inclusion. In particular, the analysis focuses on the role of these value drivers for the enactment of digital governance initiatives such as the ones related to open government and smart cities in particular. The applicability of the framework is presented through the discussion of interpretative case studies of initiatives carried out in the European municipalities of Barcelona and Tallinn. The final contribution of the chapter is expected to be the identification of a typology of e-Governance ‘attitudes’ to provide evidence of further specific interventions required for an appropriate management of similar initiatives in other countries. The chapter concludes highlighting the policy implications for administrative reform and offering practical recommendations for implementing digital governance initiatives.JRC.J.3-Information Societ