The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Bjorn Lagerblad - One of the best experts on this subject based on the ideXlab platform.
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obtaining Rheological parameters from flow Test analytical computational and lab Test approach
Cement and Concrete Research, 2014Co-Authors: Annika Gram, Johan Silfwerbrand, Bjorn LagerbladAbstract:In the mix design process of cementitious suspensions, an adequate rheology of the cement paste is crucial. A novel Rheological field Test device for cementitious fluids is presented here and investigated theoretically, by computer simulation and by lab Tests. A simple flow stoppage Test with a timed spread passage point provides accurate Rheological parameters according to the Bingham material model. Values for yield stress and plastic viscosity are obtained for a Test specimen of no more than 19.75 · 10‾⁶ m³ of fluid. This volume is equivalent to 19.75 g of water at room temperature. Such a small volume allows reliable Tests even for small amounts of fillers. Promising results show that both yield stress and plastic viscosity can be determined by this simple Test. This novel Rheological Test method also enables the correlation of different Rheological equipment used by different laboratories.
Dong Zou - One of the best experts on this subject based on the ideXlab platform.
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Fabrication and characterization of Li1+x-yNb1-x-3yTix+4yO3 substrates using aqueous tape casting process
Ceramics International, 2009Co-Authors: Shaochun Li, Qilong Zhang, Hui Yang, Dong ZouAbstract:An aqueous system for tape casting Li1+x-yNb1-x-3yTix+4yO3 (LNT) ceramics was developed using poly(vinyl alcohol) (PVA) binder, ethylene alcohol (EG) plasticizer and ammonium salt of polycarboxylate (PCA-NH4) dispersant. The zeta potential measurement showed that the isoelectric point of the LNT particles moved slightly toward more acid region after the dispersant absorbed on the particles, while the zeta potential increased significantly. The Rheological Test indicated that the ceramic slurry exhibited a typical pseudoplastic behavior without thixotropy. The effect of solid loading on the properties of the green tapes was investigated. The increase in the solid loading increased the tensile strength and the green density of the tapes. TGA analysis indicated that the organic additives in the green tapes can be completely removed by heat treatment at 600 °C. SEM micrographs showed that the microstructure of the green and sintered tapes was homogeneous. Crown Copyright © 2008.
Reetta Anderson - One of the best experts on this subject based on the ideXlab platform.
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Recycling potential of post-consumer plastic packaging waste in Finland
Waste Management, 2017Co-Authors: Helena Dahlbo, Valeria Poliakova, Olli Sahimaa, Ville Mylläri, Reetta AndersonAbstract:Recycling of plastics is urged by the need for closing material loops to maintain our natural resources when striving towards circular economy, but also by the concern raced by observations of plastic scrap in oceans and lakes. Packaging industry is the sector using the largest share of plastics, hence packaging dominates in the plastic waste flow. The aim of this paper was to sum up the recycling potential of post-consumer plastic packaging waste in Finland. This potential was evaluated based on the quantity, composition and mechanical quality of the plastic packaging waste generated by consumers and collected as a source-separated fraction, within the mixed municipal solid waste (MSW) or within energy waste.Based on the assessment 86,000-117,000 tons (18 kg/person/a) of post-consumer plastic packaging waste was generated in Finland in 2014. The majority, 84% of the waste was in the mixed MSW flow in 2014. Due to the launching of new sorting facilities and separate collections for post-consumer plastic packaging in 2016, almost 40% of the post-consumer plastic packaging could become available for recycling. However, a 50% recycling rate for post-consumer plastic packaging (other than PET bottles) would be needed to increase the overall MSW recycling rate from the current 41% by around two percentage points.The share of monotype plastics in the overall MSW plastics fraction was 80%, hence by volume the recycling potential of MSW plastics is high. Polypropylene (PP) and low density polyethylene (LDPE) were the most common plastic types present in mixed MSW, followed by polyethylene terephthalate (PET), polystyrene (PS) and high density polyethylene (HDPE). If all the Finnish plastic packaging waste collected through the three collection types would be available for recycling, then 19,000-25,000 tons of recycled PP and 6000-8000 tons of recycled HDPE would be available on the local market. However, this assessment includes uncertainties due to performing the composition study only on mixed MSW plastic fraction. In order to obtain more precise figures of the recycling potential of post-consumer plastic packaging, more studies should be performed on both the quantities and the qualities of plastic wastes.The mechanical and Rheological Test results indicated that even plastic wastes originating from the mixed MSW, can be useful raw materials. Recycled HDPE showed a smaller decline in the mechanical properties than recycled PP. The origin and processing method of waste plastic seemed to have less effect on the mechanical quality than the type of plastic. The applicability of a plastic waste for a product needs to be assessed case by case, due to product specific quality requirements. In addition to mechanical properties, the chemical composition of plastic wastes is of major importance, in order to be able to restrict hazardous substances from being circulated undesirably.In addition to quantity and quality of plastic wastes, the sustainability of the whole recycling chain needs to be assessed prior to launching operations so that the chain can be optimized to generate both environmental and economic benefits to society and operators.
Annika Gram - One of the best experts on this subject based on the ideXlab platform.
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obtaining Rheological parameters from flow Test analytical computational and lab Test approach
Cement and Concrete Research, 2014Co-Authors: Annika Gram, Johan Silfwerbrand, Bjorn LagerbladAbstract:In the mix design process of cementitious suspensions, an adequate rheology of the cement paste is crucial. A novel Rheological field Test device for cementitious fluids is presented here and investigated theoretically, by computer simulation and by lab Tests. A simple flow stoppage Test with a timed spread passage point provides accurate Rheological parameters according to the Bingham material model. Values for yield stress and plastic viscosity are obtained for a Test specimen of no more than 19.75 · 10‾⁶ m³ of fluid. This volume is equivalent to 19.75 g of water at room temperature. Such a small volume allows reliable Tests even for small amounts of fillers. Promising results show that both yield stress and plastic viscosity can be determined by this simple Test. This novel Rheological Test method also enables the correlation of different Rheological equipment used by different laboratories.
Maik Gude - One of the best experts on this subject based on the ideXlab platform.
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development and validation of a novel Rheological Test device and measurement system for determining the influence of humidity on viscosity
Polymer Testing, 2017Co-Authors: E Dohmen, R Fusel, M Muller, M Schaffler, Maik GudeAbstract:Abstract Although a strong impact of humidity on polymers and the formation of their molecular network is known, the complex interactions between humidity, temperature, diffusion, reaction kinetics, Rheological behaviour and mechanical properties are not fully understood yet. Most current approaches solely analyse the relationships between environmental conditions in a solidified or crosslinked state and the mechanical properties. In contrast, this work focusses on measuring changes in Rheological properties depending on relative humidity in the liquid state. A custom designed novel measuring geometry is introduced and validated. It enables for the first time to rheometrically investigate the influence of relative humidity on reactive systems during their cross-linking process. Our results significantly depict the influence of humidity on the cross-linking process and the gel time. The potential of the introduced measuring geometry for improving reactive systems, adapting these precisely to environmental boundary conditions or assuring product performance is hereby demonstrated. This is especially important for industrial manufacturing processes running at different production sites around the world in different climatic zones or repair processes being performed outdoor, e.g. for wind energy plants.