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Upcycling cellulose waste textile into aerogel beads via prilling technique
No full textInternational audienceThe goal is to demonstrate the possibility of upcycling waste textile into high value-added materials, aerogels. Prilling (or jet-vibration) method was used to make aerogel beads based on viscose textile and also on microcrystalline cellulose (MCC), the latter used as a reference. The solvent was ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene acetate ([DBNH][OAc]):DMSO = 50:50. The rheological properties of solutions were studied at temperatures 20–60 °C. Cellulose droplets formed under vibration were falling in ethanol coagulation bath forming alcogel beads, and the latter were dried with supercritical CO2 resulting in cellulose aerogel beads. Cellulose solution jet, droplet and alcogel bead diameters, as well as size distribution of MCC- and viscose-based aerogel beads were measured and evaluated as a function of processing conditions (nozzle size, frequency of vibration, distance between the nozzle and coagulation bath and its temperature). Correlation parameter was used to rate the impact of the processing conditions on aerogel bead roundness and aspect ratio. Highly spherical aerogel beads (aspect ratio 1.09–1.16 and roundness 94.6–96.2) based on viscose- and MCC-based solutions were obtained with the nozzle size 400 µm, vibration frequency 100 Hz and nozzle-to-bath distance 3.5 cm. Their density was 0.08–0.12 g.cm−3 and specific surface area around 400 m2.g−1. Cytotoxicity experiments demonstrated that both types of aerogels are harmless as tested on in vitro cultures
A Social BPM Approach to Deal with Agility
No full textcopyright SpringerInternational audienceBusiness Process Management (BPM) takes care of the business process (BP) lifecycle using different technologies in organizations to provide value-added services or products for end-users. Although today’s fast-changing business world poses vast variants of business processes (BPs) alongside uncertainty. This situation requires an agile BPM to manage, maintain, and execute different variants of a BP as well as deal with uncertainties and changes. One of the emphasises of agile BPM is involving stakeholders in the BP lifecycle, which requires a standard approach for all stakeholders to have quick and efficient access to the BP lifecycle to prevent problems like cultural resistance. In order to reach a standard approach, social BPM is an emerging concept that can help the easy and efficient involvement of stakeholders in the BP lifecycle. By inspiring form social BPM, this paper propose a new social media-based BPM platform to deal with different varieties of BP and uncertainties by integrating stakeholders in the BP lifecycle. While the platform eases communication, information exchange, and decision-making among stakeholders; it also eliminates the exchange between design-time and run-time while a change occurs by merging design-time and run-time
Building insulation renovation: a process and a software to assist panel layout design, a part of the ISOBIM project.
No full textInternational audienceIn order to lower the huge carbon dioxide emissions due to building heating, the goal of this communication is to show how the design of insulation panel layout can be strongly computer-aided during façade building energy renovation projects. The work has been achieved during an applied collaborative research project (ISOBIM), whose purpose is to develop open web integrated decision-aided tools to support a whole digital engineering retrofitting processes using modular timber framing panels. First, the panel layout design problem is analyzed and permit to identify a four steps design process supported by three data models. Then, once the problem is preprocessed to remove some singularities, an automatic layout design algorithm is proposed and discussed. An example illustrates the propositions and support discussion
Market Potential Estimation Framework for Circular Economy
No full textInternational audienceCircular economy brings environmental, economical and social benefits to the society.New business initiatives are encouraged to accelerate the shifting towards a circular economy. However, the scaling of new business in the circular economy is still under-researched. This study is focused on the demand aspect of business scaling, and aims to propose a holistic framework to estimate the market potential for a new business in the circular economy. The framework is composed of sets and filters, where demand forecast is deduced from the statistics of existing products and secondary market research. Quantitative and qualitative methods are both used in the framework, where clustering analysis and multi-criteria decision-making techniques are combined with expert judgement. A case study on electric retrofit of vehicles is proposed to demonstrate the application of the framewor
Crosslinked chitosan microparticles as a safe and efficient DNA carrier for intranasal vaccination against cutaneous leishmaniasis
No full textInternational audienceIntranasal (i.n.) vaccination with adjuvant-free plasmid DNA encoding the leishmanial antigen LACK (LACK DNA) has shown to induce protective immunity against both cutaneous and visceral leishmaniasis in rodents. In the present work, we sought to evaluate the safety and effectiveness of d,l-glyceraldehyde cross-linked chitosan microparticles (CCM) as a LACK DNA non-intumescent mucoadhesive delivery system. CCM with 5 μm of diameter was prepared and adsorbed with a maximum of 2.4% (w/w) of DNA with no volume alteration. Histological analysis of mouse nostrils instilled with LACK DNA / CCM showed microparticles to be not only mucoadherent but also mucopenetrant, inducing no local inflammation. Systemic safeness was confirmed by the observation that two nasal instillations one week apart did not alter the numbers of bronchoalveolar cells or blood eosinophils; did not alter ALT, AST and creatinine serum levels; and did not induce cutaneous hypersensitivity. When challenged in the footpad with Leishmania amazonensis, mice developed significantly lower parasite loads as compared with animals given naked LACK DNA or CCM alone. That was accompanied by increased stimulation of Th1-biased responses, as seen by the higher T-bet / GATA-3 ratio and IFN-γ levels. Together, these results demonstrate that CCM is a safe and effective mucopenetrating carrier that can increase the efficacy of i.n. LACK DNA vaccination against cutaneous leishmaniasis
Towards a Digital Collaborative Framework for an Efficient Medication Errors Management
No full textPart 12: Collaborative Networks in Personalized HealthcareInternational audienceThe Medication Use Process in hospitals is one of the crucial processes of the care pathways. It is defined as a highly intricate and collaborative process aiming to deliver effective and safe patient care. Indeed, it involves different stakeholders working together to provide the best treatment to the patient and manage several health conditions. This complexity can give rise to medication errors, leading to serious patient health-related consequences. Being fully aware of the significance and complexity of this process, in this work, we propose a digital collaborative framework to manage medication errors. The main goals of this framework are to assist healthcare organizations in their risk management sessions, maximize the effectiveness of the care provided, and improve patient safety and quality of car
Direct Evidence of Dynamic Metal Support Interactions in Co/TiO2 Catalysts by Near-Ambient Pressure X-ray Photoelectron Spectroscopy
No full textInternational audienceThe interaction between metal particles and the oxide support, the so-called metal–support interaction, plays a critical role in the performance of heterogenous catalysts. Probing the dynamic evolution of these interactions under reactive gas atmospheres is crucial to comprehending the structure–performance relationship and eventually designing new catalysts with enhanced properties. Cobalt supported on TiO2 (Co/TiO2) is an industrially relevant catalyst applied in Fischer−Tropsch synthesis. Although it is widely acknowledged that Co/TiO2 is restructured during the reaction process, little is known about the impact of the specific gas phase environment at the material’s surface. The combination of soft and hard X-ray photoemission spectroscopies are used to investigate in situ Co particles supported on pure and NaBH4-modified TiO2 under H2, O2, and CO2:H2 gas atmospheres. The combination of soft and hard X-ray photoemission methods, which allows for simultaneous probing of the chemical composition of surface and subsurface layers, is one of the study’s unique features. It is shown that under H2, cobalt particles are encapsulated below a stoichiometric TiO2 layer. This arrangement is preserved under CO2 hydrogenation conditions (i.e., CO2:H2), but changes rapidly upon exposure to O2. The pretreatment of the TiO2 support with NaBH4 affects the surface mobility and prevents TiO2 spillover onto Co particles
Phosphorus extracted municipal sludge-derived hydrochar as a potential solid fuel: Effects of acidic leaching and combustion mechanism
No full textInternational audienceHydrochar from hydrothermal liquefaction (HTL) of municipal sludge is often seen as waste. Initially, acidic leaching has been performed on hydrochar to recover phosphorus. This study evaluated the resulting hydrochar as solid fuel, thus achieving zero waste for integrating HTL into wastewater treatment plants. The effects of various leaching conditions on acid-modified hydrochar properties were examined. Compared to raw hydrochar, acid-modified hydrochar had a significant ash reduction (up to 44%). The leaching conditions (10 mL of 0.6 N HNO3/g for 2 h) for near-complete phosphorus extraction also achieved the following most desirable properties of acid-modified hydrochar: Maximized fuel ratio (1.3), higher heating value (20.5 MJ/kg), carbon content (48%), and minimized ash content (34%) on a dry basis. By removing most alkali and alkaline earth metals, acid-modified hydrochar could carry a low slagging and fouling risk compared to a high/severe risk for raw hydrochar. Acidic leaching also enhanced ignition temperature from 317 to 351 °C for safer storage and transportation of hydrochar, with a higher comprehensive combustion index (up to 9.9 × 10−8 min−2 °C−3). Overall, hydrochar fuel property was improved by acid modification, comparable to bituminous coal. For the first time, it was identified that hydrochar combustion was controlled by a two-step nth-order reaction mechanism f(α) = (1 − α)n with the reaction order changing from 3 to 1 as progressed. The acid modification did not affect combustion mechanisms but reduced activation energy in the first stage. The results demonstrated a sustainable approach for closing the waste loop and provided a pathway for transforming hydrochar into biofuel
Oxide Supported Cobalt Catalysts for CO 2 Hydrogenation to Hydrocarbons: Recent Progress
No full textInternational audienceCarbon capture and utilization represents a promising strategy to meet the global energy and climate goals. Under specific conditions, CO2 catalytic hydrogenation with renewable H2 can transform waste CO2 into a chemical feedstock for added-value energy carriers and chemicals. CO2-Fischer–Tropsch synthesis-based-hydrocarbons should contribute to the creation of a circular carbon economy with a significant impact on anthropogenic emission into the atmosphere. This review summarizes the progress achieved toward the single-step hydrogenation of CO2 to long-chain hydrocarbons over oxide-supported Co-based catalysts. Mechanistic aspects are discussed in relation to thermodynamic and kinetic limitations. The main parameters that must be taken into consideration to increase the activity and the selectivity toward compounds of two or more carbon atoms (C2+) are discussed in detail: cobalt active phase, support and metal-support interfaces, and promoters. Finally, particular focus is dedicated to the role of reducible oxide supports and their surface defects on the activation of CO2, as well as on the regulation and evolution of metal-support interactions
Upcycling of textile waste into high added value cellulose porous materials, aerogels and cryogels
No full textInternational audienceCellulose textile waste was upcycled into highly porous and lightweight cellulose materials. Fabrics made of cotton and regenerated cellulose were dissolved in ionic liquids, 1-ethyl-3-methyl imidazolium acetate ([EMIM][OAc]) or 1,5-diazabicyclo[4.3.0]non-5-enium acetate ([DBNH][OAc]), each mixed with dimethyl sulfoxide (DMSO). Non-solvent induced phase separation triggered by ethanol was used to obtain alcogels, which were dried either with supercritical CO2, or ethanol was exchanged with water and hydrogels were freeze-dried. Alcogels were also atmospheric pressure dried for comparison. Microcrystalline cellulose was used as a reference and processed in the same way. Materials with various porosities and morphologies were obtained. The influence of the cellulose molecular weight, the type of solvent and the drying route on materials' density, porosity, specific surface area and morphology was investigated. The importance of the coagulation pathway, or the way of demixing (instantaneous or delayed), is demonstrated as it allows us to significantly vary the material morphology