115 research outputs found

    Effect of different lignocellulosic fibres on poly(Δ-caprolactone)-based composites for potential applications in orthotics

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    This work compares the mechanical and thermal behaviour of fully biodegradable biocomposites based on polycaprolactone reinforced with three different natural fibres, namely hemp, sisal and coir, for potential applications in the field of orthoses. The same properties were further compared to those of two commercially available materials commonly used in the same prospective field. The results confirmed that the addition of natural fibres, irrespective of the origin of the fibres (leaf, bast or fruit) to a biodegradable matrix allows for significant improvement of the mechanical behaviour of the ensuing composites compared to traditional thermoplastic materials used in orthotics

    Long-Term Microgravity Effects on Isometric Handgrip and Precision Pinch Force with Visual and Proprioceptive Feedback

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    The study and analysis of human physiology during short- and long-duration space flights are the most valuable approach in order to evaluate the effect of microgravity on the human body and to develop possible countermeasures in prevision of future exploratory missions and Mars expeditions. Hand performances such as force output and manipulation capacity are fundamental for astronauts’ intra- and extravehicular activities. Previous studies on upper limb conducted on astronauts during short-term missions (10 days) indicated a temporary partial reduction in the handgrip maximum voluntary contraction (MVC) followed by a prompt recovery and adaptation to weightlessness during the last days of the mission. In the present study, we report on the “Crew’s Health: Investigation on Reduced Operability” (CHIRO) protocol, developed for handgrip and pinch force investigations, performed during the six months increment 7 and increment 8 (2003-2004) onboard International Space Station (ISS). We found that handgrip and pinch force performance are reduced during long-term increments in space and are not followed by adaptation during the mission, as conversely reported during short-term increment experiments. The application of protocols developed in space will be eligible to astronauts during long-term space missions and to patients affected by muscle atrophy diseases or nervous system injury on Earth

    Preparation and properties of adhesives based on phenolic resin containing lignin micro and nanoparticles: A comparative study

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    This work investigated, for the first time, the role of nanosized lignin (LNP), in comparison with microlignin (LMP), when introduced at two different weight amounts (5% and 10 wt%) in bulk phenol–formaldehyde resol as adhesive. Morphological analysis was performed to check out the dispersion and interfacial bonding of lignin in the phenolic resin. The curing process has been examined by differential scanning calorimetry (DSC), while the thermal stability of the composites has been evaluated by using thermogravimetric (TGA) and thermo-mechanical (TMA) analysis. Results exhibited that small amount of lignin could both favor the thermal cure reaction, due to its abundance of phenylpropane units, and the initial thermal resistance could be consequently improved, especially when the nano-sized lignin was used. Meanwhile, the effect of micro- and nano-modification on tensile shear strength of wood lap joints based on lignin-phenol–formaldehyde resol adhesives was also analyzed. Results showed that 5 wt% of LNP could positively increase the shear strength from 8.7 to 10.9 MPa, opening the possibility of using environmental friendly nanoscale lignin in cross linked traditional phenol wood adhesives with enhanced adhesion performance, strongly related to nanoparticles higher specific surface area and reactivity. Keywords: A. Resol resin, A. Lignin micro/nanoparticles, B. Thermal properties, D. Shear tes

    Revalorization of sunflower stalks as novel sources of cellulose nanofibrils and nanocrystals and their effect on wheat gluten bionanocomposite properties

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    [EN] Novel gluten based bionanocomposites reinforced with cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC) extracted from sunflower stalks by respectively a steam explosion treatment and a hydrolysis procedure, were prepared by casting/evaporation. The extracted cellulose nanomaterials, both CNC and CNF, were embedded in gluten matrix and their effect was investigated. Morphological investigations highlighted that gluten based bionanocomposites showed a homogenous morphology, the absence of visible cellulose nanoreinforcements, and the presence of holes for Gluten CNF nanocomposites. Gluten CNF showed a reduction of water vapour permeability coefficients but the values are higher respect to gluten reinforced with CNC. This behaviour could be related to the ability of CNC to increase the tortuous path of gas molecules. Moreover, the results from thermal, mechanical and barrier properties confirmed the strong interactions obtained between CNC and gluten matrix during the process. The study suggested the possibility to re-valorise agricultural wastes with potential applications as reinforcement in polymer matrix bionanocomposites. © 2016 Elsevier Ltd. All rights reservedFortunati, E.; Luzi, F.; Jiménez Marco, A.; Gopakumar, D.; Puglia, D.; Thomas, S.; Kenny, J.... (2016). Revalorization of sunflower stalks as novel sources of cellulose nanofibrils and nanocrystals and their effect on wheat gluten bionanocomposite properties. Carbohydrate Polymers. 149:357-368. doi:10.1016/j.carbpol.2016.04.120S35736814

    Endophytic Bacteria Associated with Origanum heracleoticum L. (Lamiaceae) Seeds

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    Seed-associated microbiota are believed to play a crucial role in seed germination, seedling establishment, and plant growth and fitness stimulation, due to the vertical transmission of a core microbiota from seeds to the next generations. It might be hypothesized that medicinal and aromatic plants could use the seeds as vectors to vertically transfer beneficial endophytes, providing plants with metabolic pathways that could influence phytochemicals production. Here, we investigated the localization, the structure and the composition of the bacterial endophytic population that resides in Origanum heracleoticum L. seeds. Endocellular bacteria, surrounded by a wall, were localized close to the aleurone layer when using light and transmission electron microscopy. From surface-sterilized seeds, cultivable endophytes were isolated and characterized through RAPD analysis and 16S RNA gene sequencing, which revealed the existence of a high degree of biodiversity at the strain level and the predominance of the genus Pseudomonas. Most of the isolates grew in the presence of six selected antibiotics and were able to inhibit the growth of clinical and environmental strains that belong to the Burkholderia cepacia complex. The endophytes production of antimicrobial compounds could suggest their involvement in plant secondary metabolites production and might pave the way to endophytes exploitation in the pharmaceutical field

    New direct measurement of the 10 B(p,α) 7 Be reaction with the activation technique

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    Boron plays an important role in astrophysics and, together with lithium and beryllium, is a probe of stellar structure during the pre-main sequence and main-sequence phases. In this context, the 10 B(p, α ) 7 Be reaction is of particular interest.The literature data show discrepancies in the energy range between 100 keV and 2 MeV. This also poses a normalization problem for indirect data obtained with the Trojan Horse Method.A new measurement of the 10 B(p, α ) 7 Be reaction cross section was performed at Legnaro National Laboratories (LNL). At LNL, the cross section was determined with the activation technique by measuring the activated samples at a low-background counting facility. The analysis of that experiment is now complete and the results are here presented

    Site effect studies following the 2016 Mw 6.0 Amatrice Earthquake (Italy): the Emersito Task Force activities

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    On August 24, 2016, at 01:36 UTC a MW 6.0 earthquake struck an extensive area of the Central Apennines (Italy) be-tween the towns of Norcia and Amatrice. Due to the mainshock magnitude and the widespread damaging level of build-ings in the epicentral area, the Emersito task force has been mobilized by the Istituto Nazionale di Geofisica e Vulcanologia (INGV). The aim of Emersito is to carry out and coordinate the monitoring of local site effects, caused by geological and geomorphological settings. During the first days of the seismic emergency, Emersito installed a tempo-rary seismic network for site effect studies at 4 municipalities close to the epicentral area (Amandola, Civitella del Tronto, Montereale and Capitignano), using 22 stations equipped with both velocimetric and accelerometric sensors. The selection of the sites where stations have been installed was mainly driven by the proximity to the epicentral area (without interfere with the rescue operations) and by peculiar geologic and geomorphologic settings (topographic irregu-larities, fault zones, alluvial plains). Preliminary analyses performed on ambient noise and aftershocks signals show that directional amplification effects may have occurred at stations installed on the top of topographic irregularities. We also observed the lengthening and amplification of the seismograms and a variability of the peaked frequency across the sedi-mentary basin between Montereale and Capitignano, probably related to a different thickness of the deposits. Further analyses are necessary to assess the correlation with surface geology.Published4T. Sismologia, geofisica e geologia per l'ingegneria sismica1SR. TERREMOTI - Servizi e ricerca per la SocietĂ 1IT. Reti di monitoraggioJCR Journa

    Temporary dense seismic network during the 2016 Central Italy seismic emergency for microzonation studies

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    In August 2016, a magnitude 6.0 earthquake struck Central Italy, starting a devastating seismic sequence, aggravated by other two events of magnitude 5.9 and 6.5, respectively. After the first mainshock, four Italian institutions installed a dense temporary network of 50 seismic stations in an area of 260 km2. The network was registered in the International Federation of Digital Seismograph Networks with the code 3A and quoted with a Digital Object Identifier ( https://doi.org/10.13127/SD/ku7Xm12Yy9 ). Raw data were converted into the standard binary miniSEED format, and organized in a structured archive. Then, data quality and completeness were checked, and all the relevant information was used for creating the metadata volumes. Finally, the 99 Gb of continuous seismic data and metadata were uploaded into the INGV node of the European Integrated Data Archive repository. Their use was regulated by a Memorandum of Understanding between the institutions. After an embargo period, the data are now available for many different seismological studies.Publishedid 1825T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa

    The 10B(p,α)7Be S(E)-factor from 5 keV to 1.5 MeV using the Trojan Horse Method

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    The 10 B(p, α ) 7 Be reaction is the main responsible for the 10 B destruction in stellar interior [1]. In such environments this p-capture process occurs at a Gamow energy of 10 keV and takes places mainly through a resonant state (Ex = 8.701 MeV) of the compound 11 C nucleus. Thus a resonance right in the region of the Gamow peak is expected to significantly influence the behavior of the astrophysical S(E)-factor. The 10 B(p, α ) 7 Be reaction was studied via the Trojan Horse Method (THM) applied to the 2 H( 10 B, α 7 Be)n in order to extract the astrophysical S(E)-factor in a wide energy range from 5 keV to 1.5 MeV

    New direct measurement of the 10

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    Boron plays an important role in astrophysics and, together with lithium and beryllium, is a probe of stellar structure during the pre-main sequence and main-sequence phases. In this context, the 10B(p,α)7 Be reaction is of particular interest. The literature data show discrepancies in the energy range between 100 keV and 2 MeV. This also poses a normalization problem for indirect data obtained with the Trojan Horse Method. A new measurement of the 10B(p,α)7 Be reaction cross section was performed at Legnaro National Laboratories (LNL). At LNL, the cross section was determined with the activation technique by measuring the activated samples at a low-background counting facility. The analysis of that experiment is now complete and the results are here presented
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