2,684 research outputs found

    A combination of SEM and EDX studies on a clay-based natural composite with animal fibre and its mechanical implications

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    A variety of natural fibres are nowadays being utilized as soil reinforcement. Test results demonstrate the positive effects of adding natural fibres to soils, in that they decrease shrinkage, reduce curing time and enhance compressive, flexural and shear strength if an optimum reinforcement ratio can be utilised. This paper describes a study which uses a Scanning Electron Microscope (SEM) and an Energy Diffraction Analysis of X-rays (EDX) technique on clay-based composites stabilized with natural polymer and fibres. Different dosages of fibres and several types of soils have been used in this study with the aim of determining advantageous properties for building material applications. SEM and EDX test results reveal the degree of bonding between the particles of soil and the natural fibers. This has enabled a better understanding of the micro-morphology of the natural fibers and their effect on the overall composite material structure. Microscopic analysis was combined with mechanical tests to establish the different strength characteristics of every soil

    Biobased materials from microbial biomass and its derivatives

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    There is a strong public concern about plastic waste, which promotes the development of new biobased materials. The benefit of using microbial biomass for new developments is that it is a completely renewable source of polymers, which is not limited to climate conditions or may cause deforestation, as biopolymers come from vegetal biomass. The present review is focused on the use of microbial biomass and its derivatives as sources of biopolymers to form new materials. Yeast and fungal biomass are low-cost and abundant sources of biopolymers with high promising properties for the development of biodegradable materials, while milk and water kefir grains, composed by kefiran and dextran, respectively, produce films with very good optical and mechanical properties. The reasons for considering microbial cellulose as an attractive biobased material are the conformational structure and enhanced properties compared to plant cellulose. Kombucha tea, a probiotic fermented sparkling beverage, produces a floating membrane that has been identified as bacterial cellulose as a side stream during this fermentation. The results shown in this review demonstrated the good performance of microbial biomass to form new materials, with enhanced functional properties for different applications.Fil: Cottet, Agustina Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Ramírez Tapias, Yuly Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Delgado, Juan Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: de la Osa, Orlando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Salvay, Andrés Gerardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Peltzer, Mercedes Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentin

    Search for novel biobased materials within the OLIVPOL project

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    Within the context of the project OLIVPOL, olive stone (OS) residue was successfully converted into viscous polyols, as such, or containing reinforcing stone cores, by total or partial oxypropylation, respectively. Moreover, the synthesis of new macromolecular materials using the oxypropylated products, such as polyesters and polyurethanes, demonstrated a promising approach to the production of original value-added products based on renewable resources.FCT (Project PTDC/CTM/71491/2006_FCOM-01-0124-FEDER-007156

    Emission rates of bio-based building materials, a method description for qualifying and quantifying VOC emissions

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    Biobased insulation materials offer opportunities to use vapor-open building constructions. Such constructions allow direct interaction between the biobased material and the indoor environment. This interaction raises questions about indoor air quality concerning volatile organic compounds (VOCs). This study presents results for the VOC emissions from biobased materials. It consists of two parts: 1) qualification of VOC emissions (compounds) from several biobased and non-biobased building materials, and 2) quantification of VOC emissions (emission rate) from expanded cork (biobased), particle board (semi-biobased), and EPS insulation. By quantifying the emission rate, the exposure to the released VOC emissions at room temperature in a standardized room can be compared to health limit requirements. Gas chromatography and mass spectroscopy (GC–MS) is used to derive the individual VOC emissions and the Total Volatile Organic Compounds (TVOC) from these materials. For qualification, two different sampling techniques are used in which temperature is introduced as a variable to investigate its effect on the type of compounds emitted. For quantification, the toluene equivalent approach is compared to the group equivalent approach. From the analyses it is concluded that temperature has an effect on the type of VOC compounds emitted from (biobased) materials. Results from the quantification indicate that expanded cork and particle board emit no harmful substances at a level that can affect human health. For EPS insulation, elevated levels of benzene were found to exceed healthy limits. The toluene equivalent approach for quantifying the emission, generally, underestimates the rate as compared to the more accurate group equivalent approach

    Introduction to bio-based materials and biotechnologies for eco-efficient construction

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    This chapter introduces some sustainability challenges, as well as the importance of resource efficiency and the European bioeconomy strategy. The importance of biobased materials and biotech admixtures for eco-efficient construction is summarized. The importance of changing the curriculum of civil engineering to address sustainability challenges and also enhance the collaboration between civil engineers and biotech experts is briefly discussed. Comments concerning the biobased and biotech related publication intensity of several well know civil engineering departments are also made. An outline of the book is also given

    Bridging Modeling and Certification to Evaluate Low-ILUC-Risk Practices for Biobased Materials with a User-Friendly Tool

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    Biobased materials may help to achieve a renewable, circular economy, but their impact could be similar to those of non-renewable materials. In the case of biofuels, the indirect land use change (ILUC) effects determine whether they can provide sustainability benefits compared to fossil fuels. ILUC modeling estimates have large uncertainties, making them difficult to include in a policy aiming at reducing environmental impacts. The Renewable Energy Directive (RED) II reduced ILUC estimate uncertainties by shifting the focus from ILUC environmental impacts to ILUC risk. Nevertheless, this does not take into account either certifiable additionality practices to reduce the ILUC risk for the production of biobased materials, or biobased materials other than biofuels. Here we propose a simple, user-friendly tool to bridge the gap between ILUC modeling and policy, by estimating the ILUC risk of biobased material production and to assess by how much different additionality practices can reduce that risk at different levels of the value chain. This was done by explicitly including the additionality practices in an ILUC model, simplifying the model to a spreadsheet tool that relates automatically the input provided by the user, which may be a producer or a policy maker, with a certain ILUC risk. We demonstrate the functioning of the tool on two examples: maize production in Iowa and in Romania. In Iowa, maize production is already very intensive, so the additionality practices proposed have little effect on its ILUC risk category, and the low-ILUC-risk-produced maize would amount to 0.03 t ha−1 year−1. In Romania there is ample margin for implementation of additionality practices, and thus a large potential to reduce the ILUC risk category of maize production, with low-ILUC-risk-produced maize amounting to 0.19 t ha−1 year −1

    Hydroxyapatite biobased materials for treatment and diagnosis of cancer

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    Great advances in cancer treatment have been undertaken in the last years as a consequence of the development of new antitumoral drugs able to target cancer cells with decreasing side effects and a better understanding of the behavior of neoplastic cells during invasion and metastasis. Specifically, drug delivery systems (DDS) based on the use of hydroxyapatite nanoparticles (HAp NPs) are gaining attention and merit a comprehensive review focused on their potential applications. These are derived from the intrinsic properties of HAp (e.g., biocompatibility and biodegradability), together with the easy functionalization and easy control of porosity, crystallinity and morphology of HAp NPs. The capacity to tailor the properties of DLS based on HAp NPs has well-recognized advantages for the control of both drug loading and release. Furthermore, the functionalization of NPs allows a targeted uptake in tumoral cells while their rapid elimination by the reticuloendothelial system (RES) can be avoided. Advances in HAp NPs involve not only their use as drug nanocarriers but also their employment as nanosystems for magnetic hyperthermia therapy, gene delivery systems, adjuvants for cancer immunotherapy and nanoparticles for cell imaging.Peer ReviewedPostprint (published version
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