cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14322036.v1
title: Morphological characterization of copper deposited by electrolysis influenced by presence of chloride ions

description: ABSTRACT In the present work, the effect of current density on the morphology of copper deposited by electrolysis from an acidic solution of copper sulfate in the presence and absence of chloride ions as impurities is studied. For this purpose, chronopotentiometry and scanning electron microscopy techniques are used. The study reveals that, for both situations, in the presence and absence of chloride ions, the time profiles of the cathodic potential are shifted in cathodic direction with the increase of the current density. These time profiles are associated with the simultaneous occurrence of cathodic reactions during copper electrolysis. The morphological results demonstrate a direct influence of the current density represented by transitions in the electrocrystallization mechanisms associated with nucleation and growth stages of the deposited particles. Changes in the morphological patterns are corroborated by a dendritic and granular type copper deposit in the electrolyte solution without chloride ions, in contrast to the copper deposit observed in the electrolyte solution with the presence of chloride ions, where a dendritic and laminar morphology is observed. These results clearly demonstrate the mechanistic aspects on copper electrolysis.
DOI: 10.6084/m9.figshare.14322035.v1
title: Application of electroosmotic drainage to mining environmental liabilities

description: ABSTRACT Chile is the largest copper exporter in the world. However, this leadership has significant environmental costs, such as generating large amounts of solid waste from copper ore treatment. The application of the electroosmotic drainage technique to solid residues from leaching and tailings has been proposed to address this problem. The experimental part of this work consists of an experimental design with synthetic solid matrices. The percentage of fine particles and the initial moisture level were defined as factors with three levels. The volume of drained liquid was defined as the response variable. The results showed that electroosmotic drainage was more efficient than gravitational drainage when the moisture content and the percentage of fine material were at their highest levels. The effect of the factors and their interaction was corroborated by an analysis of variance. Finally, an equation was developed to describe the relationship between the response variables and the model factors.
DOI: 10.6084/m9.figshare.14322035
title: Application of electroosmotic drainage to mining environmental liabilities

description: ABSTRACT Chile is the largest copper exporter in the world. However, this leadership has significant environmental costs, such as generating large amounts of solid waste from copper ore treatment. The application of the electroosmotic drainage technique to solid residues from leaching and tailings has been proposed to address this problem. The experimental part of this work consists of an experimental design with synthetic solid matrices. The percentage of fine particles and the initial moisture level were defined as factors with three levels. The volume of drained liquid was defined as the response variable. The results showed that electroosmotic drainage was more efficient than gravitational drainage when the moisture content and the percentage of fine material were at their highest levels. The effect of the factors and their interaction was corroborated by an analysis of variance. Finally, an equation was developed to describe the relationship between the response variables and the model factors.
DOI: 10.6084/m9.figshare.14322042
title: Comparative analysis of fretting fatigue resistance between overhead conductors made of aluminum alloys 900 MCM and 823 MCM

description: ABSTRACT The electric transmission and distribution industries and utilities are looking for the most optimized components for their transmission lines. Thus, there is a need to improve the formation of the overhead conductor, which is the costliest element of electric transmission lines. Under these circumstances, conductors formed solely of aluminum wires appear to be more advantageous over aluminum conductor steel reinforced, obtaining better ampacity/weight ratios, thus lowering the transmission cost. The objective of this article was to verify the influence of the fretting fatigue phenomenon under controlled conditions, on the AA 6201 T81 and AA 1120 H19 aluminum alloy wires, which form the overhead conductors CAL 900 MCM and CAL 823 MCM, respectively. To achieve these goals, an experimental program was created capable of acquiring the data on the fatigue life of the overhead conductors and the wires separately, in order to verify the influence of fretting under a 750 N normal contact load parameter. In the results, the CAL 900 MCM achieved the lowest fatigue life, despite it made of an alloy with better mechanical properties. The same result was obtained in the fretting fatigue tests on wires, so it can be inferred that the AA 6201 T81 alloy, although it has better fatigue resistance, is more susceptible to failure in the presence of fretting when compared to AA 1120 H19 alloy.
DOI: 10.6084/m9.figshare.14322044
title: Calibration of Concrete Damaged Plasticity Model parameters for shear walls

description: ABSTRACT Reinforced concrete structures are relatively complex to analyze, with nonlinear effects like cracking, crushing, steel yielding, aggregate interlock, dowel effect, concrete-rebar interaction and so on. The concrete damaged plasticity CDP model is a consolidated smeared-crack model which accounts for multiaxial behavior with good agreement to experimental results. One particular relevant application which benefits greatly from such feature is the shear wall, as shear stress significantly influences its overall behavior, therefore multiaxial constitutive models and three-dimensional finite elements usage consist in a fitting modeling approach. Reinforced concrete shear walls are structures especially useful for lateral force-resisting systems, as they provide ductility, stiffness and strength. Albeit CDP is widely applied, its parameters are not consensus in the literature, which represents a relevant research gap. The present work considers and compares CDP parameters from relevant literature, in order to calibrate those parameters for the case of reinforced concrete shear walls. To this purpose, four wall experiments related in the bibliography are modeled using solid finite elements for concrete and trusses for rebars using commercial package ABAQUS. All walls are flexure-controlled with aspect ratio greater than 2.0. By varying those parameters and comparing obtained force vs. displacement curves and interesting values attained, like yield lateral force and displacement, stiffness and maximum lateral force, it is settled a set of parameters with acceptable response focusing in the post-peak response based on the lower estimated error of displacement capacity. Those parameters agree reasonably with literature, although it is possible that obtained calibration is restricted to flexure controlled shear walls scope. It is possible that usage of trusses to represent reinforcement does not consider dowel effect, so a suggestion for future studies is to change trusses for elements with transverse stiffness, like beams or solids.
DOI: 10.6084/m9.figshare.14322044.v1
title: Calibration of Concrete Damaged Plasticity Model parameters for shear walls

description: ABSTRACT Reinforced concrete structures are relatively complex to analyze, with nonlinear effects like cracking, crushing, steel yielding, aggregate interlock, dowel effect, concrete-rebar interaction and so on. The concrete damaged plasticity CDP model is a consolidated smeared-crack model which accounts for multiaxial behavior with good agreement to experimental results. One particular relevant application which benefits greatly from such feature is the shear wall, as shear stress significantly influences its overall behavior, therefore multiaxial constitutive models and three-dimensional finite elements usage consist in a fitting modeling approach. Reinforced concrete shear walls are structures especially useful for lateral force-resisting systems, as they provide ductility, stiffness and strength. Albeit CDP is widely applied, its parameters are not consensus in the literature, which represents a relevant research gap. The present work considers and compares CDP parameters from relevant literature, in order to calibrate those parameters for the case of reinforced concrete shear walls. To this purpose, four wall experiments related in the bibliography are modeled using solid finite elements for concrete and trusses for rebars using commercial package ABAQUS. All walls are flexure-controlled with aspect ratio greater than 2.0. By varying those parameters and comparing obtained force vs. displacement curves and interesting values attained, like yield lateral force and displacement, stiffness and maximum lateral force, it is settled a set of parameters with acceptable response focusing in the post-peak response based on the lower estimated error of displacement capacity. Those parameters agree reasonably with literature, although it is possible that obtained calibration is restricted to flexure controlled shear walls scope. It is possible that usage of trusses to represent reinforcement does not consider dowel effect, so a suggestion for future studies is to change trusses for elements with transverse stiffness, like beams or solids.
DOI: 10.6084/m9.figshare.14322045.v1
title: Production and characterization of gypsum-based composites reinforced with cocoa agroindustry waste particles

description: ABSTRACT This work aimed to produce and characterize gypsum-based composites reinforced with cocoa waste particles as a way to add value to this agricultural by-product and create an innovative material. For the production of composites, thin plaster for casting and particles of cocoa waste were used. The reinforcement proportions inserted were 0.0%; 2.5%; 5.0%; 7.5% and 10.0% replacing plaster mass. For the production of composites, wooden molds with dimensions of 40 x 40 x 160 mm were used. Analysis of the chemical composition of the cocoa waste was performed to determine the levels of total extracts, ash, lignin and holocellulose. The composites were evaluated in physical, mechanical, thermal and acoustic tests. It was found that there were improvements in physical properties with the addition of reinforcement making the material lighter, given the reduction in density (1190.69 to 1138.92 kg/m³), ??and providing a decrease in hygroscopicity, with moisture levels decreasing from 7.74 to 4.01% and water absorption decreasing from 18.37 to 5.28%. Likewise, the thermal resistance gradually increased over the treatments with values ??from 1.90 to 2.41 K.m/W and the acoustic insulation was higher in composites compared to pure plaster, although there was no linearity between treatments. As for the mechanical properties, there was a decrease in resistance both to flexion (3.60 to 0.84 MPa) and to compression (4.43 to 1.73 MPa). It was concluded that the cocoa waste has the potential to be used in the composite considering that the inclusion of up to 8.15% of the same met the standard in all tests performed. This promotes the idea that lignocellulosic waste is a promising alternative for creating materials with high added value.
DOI: 10.6084/m9.figshare.14322045
title: Production and characterization of gypsum-based composites reinforced with cocoa agroindustry waste particles

description: ABSTRACT This work aimed to produce and characterize gypsum-based composites reinforced with cocoa waste particles as a way to add value to this agricultural by-product and create an innovative material. For the production of composites, thin plaster for casting and particles of cocoa waste were used. The reinforcement proportions inserted were 0.0%; 2.5%; 5.0%; 7.5% and 10.0% replacing plaster mass. For the production of composites, wooden molds with dimensions of 40 x 40 x 160 mm were used. Analysis of the chemical composition of the cocoa waste was performed to determine the levels of total extracts, ash, lignin and holocellulose. The composites were evaluated in physical, mechanical, thermal and acoustic tests. It was found that there were improvements in physical properties with the addition of reinforcement making the material lighter, given the reduction in density (1190.69 to 1138.92 kg/m³), ??and providing a decrease in hygroscopicity, with moisture levels decreasing from 7.74 to 4.01% and water absorption decreasing from 18.37 to 5.28%. Likewise, the thermal resistance gradually increased over the treatments with values ??from 1.90 to 2.41 K.m/W and the acoustic insulation was higher in composites compared to pure plaster, although there was no linearity between treatments. As for the mechanical properties, there was a decrease in resistance both to flexion (3.60 to 0.84 MPa) and to compression (4.43 to 1.73 MPa). It was concluded that the cocoa waste has the potential to be used in the composite considering that the inclusion of up to 8.15% of the same met the standard in all tests performed. This promotes the idea that lignocellulosic waste is a promising alternative for creating materials with high added value.
DOI: 10.6084/m9.figshare.14322047
title: Study of the interaction of the bioactive compound saponin from Glycyrrhiza glabra with a carbon nanotube matrix

description: ABSTRACT Saponins are bioactive compounds belonging to the secondary metabolism of plants widely used for their beneficial actions to human health. In this work the association of the saponin from Glycyrrhiza glabra with a matrix of multi-walled carbon nanotubes was promoted to obtain a composite material with improved functional characteristics. For this investigation, chemically modified electrodes (CME) based on carbon paste were developed. Firstly, a carbon paste electrode (CPE) modified with the addition of saponin (SAP) was developed. For the electrochemical optimization of this system, CPE/SAP, studies were carried out using cyclic voltammetry. The determination of parameters such as formal potential (Eo) and potential separation (?E) indicated that the saponin used as a carbon paste modifying agent generated a matrix that favors the transfer of electrons even at low applied potentials. The second step was performed by preparing the modified carbon paste electrode with the carbon nanotube matrix (CPE/CNT). This material, surprisingly, showed a redox pair probably due to the presence of iron atoms from the preparation method, something very beneficial for the purposes of this work. Next the saponin was associated to the carbon nanotube matrix in order to investigate the behavior of the hybrid material formed (CPE/SAP-CNT), which evidenced a significant improvement in the electron transfer process when the saponin interacts with the carbon nanotube matrix, increasing the anodic peak current by more than 3.6 times in relation to the CPE/SAP and 2.1 times when compared to the CPE/CNT. Another important issue concerns the stability of the systems, with the saponin associated with the carbon nanotube matrix presenting significantly improved stability, being able to be used for more than 8 hours or 200 voltammetric cycles with loss of signal of the order of only 2%, while the CPE/SAP showed a 60% loss of signal under the same conditions of use.
DOI: 10.6084/m9.figshare.14322047.v1
title: Study of the interaction of the bioactive compound saponin from Glycyrrhiza glabra with a carbon nanotube matrix

description: ABSTRACT Saponins are bioactive compounds belonging to the secondary metabolism of plants widely used for their beneficial actions to human health. In this work the association of the saponin from Glycyrrhiza glabra with a matrix of multi-walled carbon nanotubes was promoted to obtain a composite material with improved functional characteristics. For this investigation, chemically modified electrodes (CME) based on carbon paste were developed. Firstly, a carbon paste electrode (CPE) modified with the addition of saponin (SAP) was developed. For the electrochemical optimization of this system, CPE/SAP, studies were carried out using cyclic voltammetry. The determination of parameters such as formal potential (Eo) and potential separation (?E) indicated that the saponin used as a carbon paste modifying agent generated a matrix that favors the transfer of electrons even at low applied potentials. The second step was performed by preparing the modified carbon paste electrode with the carbon nanotube matrix (CPE/CNT). This material, surprisingly, showed a redox pair probably due to the presence of iron atoms from the preparation method, something very beneficial for the purposes of this work. Next the saponin was associated to the carbon nanotube matrix in order to investigate the behavior of the hybrid material formed (CPE/SAP-CNT), which evidenced a significant improvement in the electron transfer process when the saponin interacts with the carbon nanotube matrix, increasing the anodic peak current by more than 3.6 times in relation to the CPE/SAP and 2.1 times when compared to the CPE/CNT. Another important issue concerns the stability of the systems, with the saponin associated with the carbon nanotube matrix presenting significantly improved stability, being able to be used for more than 8 hours or 200 voltammetric cycles with loss of signal of the order of only 2%, while the CPE/SAP showed a 60% loss of signal under the same conditions of use.
DOI: 10.6084/m9.figshare.14322048
title: Obtaining and characterizing tridirectional aramid fiber multilayered fabric for ballistic shielding application

description: ABSTRACT The use of fabrics in the processing of composite materials is already a reality due to the attractive mechanical properties that this type of reinforcement adds to the final material and the greater ease of processing. However, laminated composites are susceptible to failure by delamination between the layers. In this case, the use of reinforcements based on tridirectional multilayer fabrics (3D-fabrics) with filaments in orthogonal directions could better contribute in order to enhance composite performance, reducing this type of failure. However, access to 3D-fabrics is still very restricted worldwide, due to the technological complexity involved in processing. For this purpose, the present work aims to contribute to composite processing area by producing a 3D-fabric with aramid fibers. The fabric was obtained through the production and combination of 6 layers of bidirectional fabric, simultaneously with the bonding of the layers by warp filaments, a process carried out in a single step. For this, a conventional loom was adapted and the 3D-fabric manufactured was characterized by typical tests in the textile industry, as grammage, linear density, and thickness, additionally stereoscopy analysis, tensile and drop tests were assessed. The stereoscopic analysis has revealed details from transversal and orthogonal directions of the fabric, which associated with the textile industry test results proved the success of manufactured 3D-fabric, with physical characteristics consistent with the intended arrangement. Comparatively, the results of tensile strength showed that the 3D-fabric has greater elongation than the commercial 2D-fabric. Under 40 J impact, 3D-fabric withstood without perforation and delamination between layers, an improvement when compared to 2D-fabric.
DOI: 10.6084/m9.figshare.14322048.v1
title: Obtaining and characterizing tridirectional aramid fiber multilayered fabric for ballistic shielding application

description: ABSTRACT The use of fabrics in the processing of composite materials is already a reality due to the attractive mechanical properties that this type of reinforcement adds to the final material and the greater ease of processing. However, laminated composites are susceptible to failure by delamination between the layers. In this case, the use of reinforcements based on tridirectional multilayer fabrics (3D-fabrics) with filaments in orthogonal directions could better contribute in order to enhance composite performance, reducing this type of failure. However, access to 3D-fabrics is still very restricted worldwide, due to the technological complexity involved in processing. For this purpose, the present work aims to contribute to composite processing area by producing a 3D-fabric with aramid fibers. The fabric was obtained through the production and combination of 6 layers of bidirectional fabric, simultaneously with the bonding of the layers by warp filaments, a process carried out in a single step. For this, a conventional loom was adapted and the 3D-fabric manufactured was characterized by typical tests in the textile industry, as grammage, linear density, and thickness, additionally stereoscopy analysis, tensile and drop tests were assessed. The stereoscopic analysis has revealed details from transversal and orthogonal directions of the fabric, which associated with the textile industry test results proved the success of manufactured 3D-fabric, with physical characteristics consistent with the intended arrangement. Comparatively, the results of tensile strength showed that the 3D-fabric has greater elongation than the commercial 2D-fabric. Under 40 J impact, 3D-fabric withstood without perforation and delamination between layers, an improvement when compared to 2D-fabric.
DOI: 10.6084/m9.figshare.14322050
title: Physical, mechanical and thermal properties of low-density polyethylene reinforced with PET-coated SBS paperboard shavings applying different processing conditions

description: ABSTRACT Awareness about environmental problems has generated interest in the research for new materials in line with the sustainability principles. The recycling of industrial solid waste has contributed to the transformation of environmental liabilities into new products with added commercial value. In this study, the physical, me-chanical and thermal properties of low-density polyethylene (LDPE) composites reinforced with polyeth-ylene terephthalate (PET)-coated solid bleached sulfate (SBS) paperboard shavings were investigated ac-cording to composite formation process variables: preparation temperature, mean particle diameter of com-ponents and reinforcement concentration. Very few studies on the characterization of composites reinforced with PET-coated SBS paperboard shavings have been reported to date. The analyses were carried out based on standard methods published by the American Society for Testing and Materials. The results indicate an increase in the moisture content and water absorption occurred as a function of the increase in the rein-forcement. With regard to the density, there was no significant influence of variations in the granulometry or concentration of the PET-coated SBS paperboard shavings. Composites formed with particles of 0.73 mm at 140 ºC presented satisfactory tensile and flexural strength, compared with the values for the LDPE resin. Composites with 20% reinforcement formed by particles of 4.05 mm at 140 ºC showed 14% improvement in impact resistance properties. The thermal analysis indicated that shavings degradation occurred at 190 °C. Thus lower temperatures need to be applied in the processing of this composite material. The processing conditions of the composites resulted in different performance for each evaluated property. The use of the composite in manufacturing products must follow the process conditions that will provide to material the desirable level of properties for the best performance of the final product.