cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.9900083
title: Ballistic Behavior of New Alumina Composites Reinforced with Niobo-Phosphate Glass

description: This work aimed to produce and evaluate the ballistic behavior of niobo-phosphate glass-doped alumina composites. The niobo-phosphate glass (30% Nb2O5- 30% P2O5- 20% CaO - 20% CaF2, by mol) were added to the alumina in six different weight percentages. The composite with the highest densification, measured by the Archimedes assay, was used for the ballistic tests. X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray spectroscopy by dispersive energy (EDX) were also performed. The sintered samples were enveloped on two 1020 steel plates for the residual velocity test. The best results of densification were obtained for the niobo-phosphate glass addition of 4 wt%, which was not detected the AlPO4 phase formation. From the residual velocity test, it was observed a better energy absorption for the doped alumina, in relation to pure alumina. Therefore, it is indicated that the niobo-phosphate glass addition of 4 wt% worked properly as sintering aid for alumina, enhancing its properties and performance.
DOI: 10.6084/m9.figshare.9900083.v1
title: Ballistic Behavior of New Alumina Composites Reinforced with Niobo-Phosphate Glass

description: This work aimed to produce and evaluate the ballistic behavior of niobo-phosphate glass-doped alumina composites. The niobo-phosphate glass (30% Nb2O5- 30% P2O5- 20% CaO - 20% CaF2, by mol) were added to the alumina in six different weight percentages. The composite with the highest densification, measured by the Archimedes assay, was used for the ballistic tests. X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray spectroscopy by dispersive energy (EDX) were also performed. The sintered samples were enveloped on two 1020 steel plates for the residual velocity test. The best results of densification were obtained for the niobo-phosphate glass addition of 4 wt%, which was not detected the AlPO4 phase formation. From the residual velocity test, it was observed a better energy absorption for the doped alumina, in relation to pure alumina. Therefore, it is indicated that the niobo-phosphate glass addition of 4 wt% worked properly as sintering aid for alumina, enhancing its properties and performance.
DOI: 10.6084/m9.figshare.9986114.v1
title: Evaluation of Dynamic Mechanical Properties of Fique Fabric/Epoxy Composites

description: The fique is a plant typical of the Colombian Andes, from which relatively common items are fabricated. One of these is woven fabric extensively applied in sackcloths. The mechanical strength of fique fabric have motivated recent investigations on possible reinforcement of polymer matrix composites. For this purpose its thermo-mechanical behavior was unveiled. In particular, dynamic mechanical analysis (DMA) of fique fabric reinforced polyester matrix composites disclosed improved viscoelastic behavior in association with change in the glass transition temperature. The present work extends this investigation to epoxy matrix, which is one of the most employed thermoset polymer for composite matrix. Fique fabric volumetric fractions of up to 50% are for the first time incorporated into epoxy composites. It was found that these incorporations significantly increased the viscoelastic stiffness of the composite, given by the storage modulus (E’), in the temperature interval from -50 to 170°C. An accentuated softening in viscoelastic stiffness was revealed for all composites above 75°C. Peaks in both the loss modulus (E”) and tangent delta (tan δ), respectively associated with the lower and upper limits of the glass transition temperature, were shifted towards higher temperatures with increasing amount of fique fabric.
DOI: 10.6084/m9.figshare.9986114
title: Evaluation of Dynamic Mechanical Properties of Fique Fabric/Epoxy Composites

description: The fique is a plant typical of the Colombian Andes, from which relatively common items are fabricated. One of these is woven fabric extensively applied in sackcloths. The mechanical strength of fique fabric have motivated recent investigations on possible reinforcement of polymer matrix composites. For this purpose its thermo-mechanical behavior was unveiled. In particular, dynamic mechanical analysis (DMA) of fique fabric reinforced polyester matrix composites disclosed improved viscoelastic behavior in association with change in the glass transition temperature. The present work extends this investigation to epoxy matrix, which is one of the most employed thermoset polymer for composite matrix. Fique fabric volumetric fractions of up to 50% are for the first time incorporated into epoxy composites. It was found that these incorporations significantly increased the viscoelastic stiffness of the composite, given by the storage modulus (E’), in the temperature interval from -50 to 170°C. An accentuated softening in viscoelastic stiffness was revealed for all composites above 75°C. Peaks in both the loss modulus (E”) and tangent delta (tan δ), respectively associated with the lower and upper limits of the glass transition temperature, were shifted towards higher temperatures with increasing amount of fique fabric.
DOI: 10.6084/m9.figshare.9985844
title: Effects of Gamma Radiation on the Properties of the Thermoplastic Starch/Poly (Butylene Adipate-co-Terephthalate) Blends

description: The development of blends made from matrices of synthetic biodegradable polymers, and natural additives, are considered less environmentally aggressive materials. This work aimed to study the effects of gamma radiation on the properties of the thermoplastic starch (TPS)/poly(butylene adipate-co-terephthalate) (PBAT). In this work, blends of TPS/PBAT were prepared with glycerol, castor oil and TWEEN® 80, which were prepared by extrusion and then subjected to the radiation process and characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results demonstrated increased thermal degradation for the F2 (composed by OM) and F3 (composed by OM and TWEEN® 80) regarding F0 (composed by glycerol) e F1 (composed by glycerol and TWEEN® 80) blends. A good blend component chemical interaction and partial miscibility for the blends F0 and F1 was observed and compared to the others. However, F2 and F3 blends did not present co-continuous phases; being that the XRD curve patterns were not altered by the gamma radiation. The tests performed demonstrated that the irradiated and non-irradiated samples did not have their properties significantly altered. Thus, it was concluded that it is feasible to replace castor oil with glycerol in TPS/PBAT blends.
DOI: 10.6084/m9.figshare.9986120
title: Development of Sustainable Eggshell Waste-Polyester Resin Composite Material for Using as Artificial Rock

description: The aim of this work was to study the possibility of reuse of chicken eggshell waste produced in the food manufacturing industry for processing of sustainable eggshell waste-polyester resin composite materials for use as artificial carbonaceous rocks. For this purpose, composite specimens with different eggshell waste-polyester resin compositions in different particle sizes of the eggshell waste were prepared. The technical properties (flexural strength, water absorption, apparent porosity, and bulk density), microstructural evolution, and phase analysis of the produced composite materials were investigated. The results indicated that the composite materials containing up to 65 wt.% of chicken eggshell waste with flexural strength between 31.23 and 52.06 MPa, water absorption between 0.59 and 1.37 %, apparent porosity between 0.99 and 2.28 %, and bulk density between 1.59 and 1.71 g/cm3 are highly attractive for be used as sustainable artificial carbonaceous rocks in the civil construction.
DOI: 10.6084/m9.figshare.9986120.v1
title: Development of Sustainable Eggshell Waste-Polyester Resin Composite Material for Using as Artificial Rock

description: The aim of this work was to study the possibility of reuse of chicken eggshell waste produced in the food manufacturing industry for processing of sustainable eggshell waste-polyester resin composite materials for use as artificial carbonaceous rocks. For this purpose, composite specimens with different eggshell waste-polyester resin compositions in different particle sizes of the eggshell waste were prepared. The technical properties (flexural strength, water absorption, apparent porosity, and bulk density), microstructural evolution, and phase analysis of the produced composite materials were investigated. The results indicated that the composite materials containing up to 65 wt.% of chicken eggshell waste with flexural strength between 31.23 and 52.06 MPa, water absorption between 0.59 and 1.37 %, apparent porosity between 0.99 and 2.28 %, and bulk density between 1.59 and 1.71 g/cm3 are highly attractive for be used as sustainable artificial carbonaceous rocks in the civil construction.
DOI: 10.6084/m9.figshare.10025696
title: Frequency Selective Surface Properties of Microwave New Absorbing Porous Carbon Materials Embedded in Epoxy Resin

description: In this manuscript, the electromagnetic wave absorption properties of sustainable porous carbon composites were evaluated over the X-band frequency range (8.2 - 12.4 GHz). The porous carbon material was made from the byproduct of cellulose production and was used as additive on the development of radar absorbing material (RAM) composites. These porous carbon materials have different characteristics, such as porosity size (180 µm &lt; Ø1 &lt; 250 µm and 425 µm &lt; Ø2 &lt; 500 µm) and particle size (ϕ1 &lt; 250 µm and 250 µm &lt; ϕ2 &lt; 425 µm). Composite materials were also studied as frequency selective surface (FSS) structures. It was shown how complex permittivity and reflection loss (RL) can be manipulated over the frequency range using FSS structure. While regular RAM presented RL of 19 dB at ~11.8 GHz, FSS structure presented a RL of 19 dB shifted to 12.4 GHz regarding the same carbon porous material (with particles between 250 and 425 µm and porosity between 180 and 250 µm). It was demonstrated here the potential use of sustainable porous carbon as RAM, and how FSS structure can be used to tune the frequency of the RL maximum peak.
DOI: 10.6084/m9.figshare.10025696.v1
title: Frequency Selective Surface Properties of Microwave New Absorbing Porous Carbon Materials Embedded in Epoxy Resin

description: In this manuscript, the electromagnetic wave absorption properties of sustainable porous carbon composites were evaluated over the X-band frequency range (8.2 - 12.4 GHz). The porous carbon material was made from the byproduct of cellulose production and was used as additive on the development of radar absorbing material (RAM) composites. These porous carbon materials have different characteristics, such as porosity size (180 µm &lt; Ø1 &lt; 250 µm and 425 µm &lt; Ø2 &lt; 500 µm) and particle size (ϕ1 &lt; 250 µm and 250 µm &lt; ϕ2 &lt; 425 µm). Composite materials were also studied as frequency selective surface (FSS) structures. It was shown how complex permittivity and reflection loss (RL) can be manipulated over the frequency range using FSS structure. While regular RAM presented RL of 19 dB at ~11.8 GHz, FSS structure presented a RL of 19 dB shifted to 12.4 GHz regarding the same carbon porous material (with particles between 250 and 425 µm and porosity between 180 and 250 µm). It was demonstrated here the potential use of sustainable porous carbon as RAM, and how FSS structure can be used to tune the frequency of the RL maximum peak.
DOI: 10.6084/m9.figshare.9985991
title: Effect of The Incorporation of Micro and Nanoparticles of Calcium Carbonate in Poly (Vinyl Chloride) Matrix for Industrial Application

description: This study aimed at evaluating the effects of the incorporation of micro and nanoparticles of CaCO3 on the properties of poly(vinyl chloride) (PVC), intended to industrial application. The PVC compounds added with particles of different sizes were achieved in an intensive mixer. Rheological, microstructural, mechanical and thermal properties of the compounds obtained were evaluated. The rheology test showed that the compound with the addition of two-particle size plasticized faster compared than other formulations. Microstructural analysis showed a poor particle size distribution for the micro-CaCO3 charges, and the nano-CaCO3 samples have agglomerated particles. The thermal analysis showed the compound added with two particle size with higher gelation, and in the loss modulus E’ and E”, the values also were close. The analyses showed that the combination of the two-particle sizes presented superior results when compared with the micro or nano used singly.
DOI: 10.6084/m9.figshare.9985991.v1
title: Effect of The Incorporation of Micro and Nanoparticles of Calcium Carbonate in Poly (Vinyl Chloride) Matrix for Industrial Application

description: This study aimed at evaluating the effects of the incorporation of micro and nanoparticles of CaCO3 on the properties of poly(vinyl chloride) (PVC), intended to industrial application. The PVC compounds added with particles of different sizes were achieved in an intensive mixer. Rheological, microstructural, mechanical and thermal properties of the compounds obtained were evaluated. The rheology test showed that the compound with the addition of two-particle size plasticized faster compared than other formulations. Microstructural analysis showed a poor particle size distribution for the micro-CaCO3 charges, and the nano-CaCO3 samples have agglomerated particles. The thermal analysis showed the compound added with two particle size with higher gelation, and in the loss modulus E’ and E”, the values also were close. The analyses showed that the combination of the two-particle sizes presented superior results when compared with the micro or nano used singly.
DOI: 10.6084/m9.figshare.10025564
title: Evaluation of the Projectile's loss of Energy in Polyester Composite Reinforced with Fique Fiber and Fabric

description: Firearms threat has always been a matter of personal concern, especially to soldiers in armed conflicts as well as police officers and civilians involved with public security. A multilayered armor system (MAS) is intended to personal protection against high kinetic energy ammunition, such as that used in rifles. MAS layers are normally composed of a front ceramic followed by a layer that must show both high impact resistance and low weight. Usually, synthetic fiber fabrics, such as aramid in Kevlar® and ultra-high molecular weight polyethylene (UHMWP) in Dyneema® are commonly used as the second layer. Currently, composites reinforced with natural fibers are also being considered as second MAS layer due to their good performance associated with the advantages of being cheaper and environmentally friendly. The fique is a relatively unknown natural fiber extracted from leaves of a plant native of South American Andes. In the present work, fique fibers and fique fabrics incorporated in polyester composite plates with volume fraction of 10, 20 and 30% were ballistic tested. The calculated projectile loss of energy indicated a relatively large energy dissipation by the composite. The tested specimens were statistically treated by the Weibull analysis and were examined by scanning electron microscopy.
DOI: 10.6084/m9.figshare.10025564.v1
title: Evaluation of the Projectile's loss of Energy in Polyester Composite Reinforced with Fique Fiber and Fabric

description: Firearms threat has always been a matter of personal concern, especially to soldiers in armed conflicts as well as police officers and civilians involved with public security. A multilayered armor system (MAS) is intended to personal protection against high kinetic energy ammunition, such as that used in rifles. MAS layers are normally composed of a front ceramic followed by a layer that must show both high impact resistance and low weight. Usually, synthetic fiber fabrics, such as aramid in Kevlar® and ultra-high molecular weight polyethylene (UHMWP) in Dyneema® are commonly used as the second layer. Currently, composites reinforced with natural fibers are also being considered as second MAS layer due to their good performance associated with the advantages of being cheaper and environmentally friendly. The fique is a relatively unknown natural fiber extracted from leaves of a plant native of South American Andes. In the present work, fique fibers and fique fabrics incorporated in polyester composite plates with volume fraction of 10, 20 and 30% were ballistic tested. The calculated projectile loss of energy indicated a relatively large energy dissipation by the composite. The tested specimens were statistically treated by the Weibull analysis and were examined by scanning electron microscopy.
DOI: 10.6084/m9.figshare.10025531
title: Nanoparticles of Ni1-x Znx Fe2 O4 used as Microwave Absorbers in the X-band

description: Ferrites nanoparticles of Ni1-xZnxFe2O4 ferrites with x varying between 0 and 1, in steps of 0.2, were obtained by solution combustion synthesis (SCS) and dispersed in oil paint at the concentrations of 10, 20, 30 and 40% by ferrite weight of ferrite, with the aim of producing electromagnetic wave absorbing composites, in the X band (8-12 GHz). The ferrite powders obtained were characterized by X-ray diffraction (XRD), and to determine to mean crystallite size, crystallographic phases, as well as lattice parameters, was used the Rietveld method. The XRD results revealed the majority presence of the spinel cubic ferrite phase for all stoichiometries with crystallite size between 44 and 81 nm. The composites were characterized by the rectangular waveguide transmission line method to measure the absorption of the electromagnetic wave in the X band. The nanocomposites with 40% of NiFe2O4 and Ni0.8Zn0.2Fe2O4 presented the highest electromagnetic wave absorption performance.
DOI: 10.6084/m9.figshare.10025531.v1
title: Nanoparticles of Ni1-x Znx Fe2 O4 used as Microwave Absorbers in the X-band

description: Ferrites nanoparticles of Ni1-xZnxFe2O4 ferrites with x varying between 0 and 1, in steps of 0.2, were obtained by solution combustion synthesis (SCS) and dispersed in oil paint at the concentrations of 10, 20, 30 and 40% by ferrite weight of ferrite, with the aim of producing electromagnetic wave absorbing composites, in the X band (8-12 GHz). The ferrite powders obtained were characterized by X-ray diffraction (XRD), and to determine to mean crystallite size, crystallographic phases, as well as lattice parameters, was used the Rietveld method. The XRD results revealed the majority presence of the spinel cubic ferrite phase for all stoichiometries with crystallite size between 44 and 81 nm. The composites were characterized by the rectangular waveguide transmission line method to measure the absorption of the electromagnetic wave in the X band. The nanocomposites with 40% of NiFe2O4 and Ni0.8Zn0.2Fe2O4 presented the highest electromagnetic wave absorption performance.
DOI: 10.6084/m9.figshare.10026149
title: Firing Behavior of the Clay Fraction of a Natural Kaolinitic Clay: Are They Different?

description: A comparative investigation on the firing behavior of a natural kaolinitic clay from Campos dos Goytacazes, Brazil, and its specific clay fraction was performed. The clay fraction, equivalent diameter less than 2 µm, was separated from the precursor clay by a sedimentation method. Chemical analysis, X-ray diffraction (XRD) and scanning electron microscopy were used to characterize the unfired materials. Thermoanalysis and dilatometry were applied to follow the structural transformations. The firing behavior was studied by water absorption and XRD of samples fired in the temperature range from 400 to 1100°C. Differences were found between the natural kaolinitic clay and its clay fraction. The absence of quartz and smaller particles of the clay fraction result in a comparatively lower temperature for structural consolidation associated with reduced open porosity. This can be attributed to solid state sintering alone, in contrast to a higher temperature liquid phase sintering needed for complete consolidation of the natural kaolinitic clay.
DOI: 10.6084/m9.figshare.10026149.v1
title: Firing Behavior of the Clay Fraction of a Natural Kaolinitic Clay: Are They Different?

description: A comparative investigation on the firing behavior of a natural kaolinitic clay from Campos dos Goytacazes, Brazil, and its specific clay fraction was performed. The clay fraction, equivalent diameter less than 2 µm, was separated from the precursor clay by a sedimentation method. Chemical analysis, X-ray diffraction (XRD) and scanning electron microscopy were used to characterize the unfired materials. Thermoanalysis and dilatometry were applied to follow the structural transformations. The firing behavior was studied by water absorption and XRD of samples fired in the temperature range from 400 to 1100°C. Differences were found between the natural kaolinitic clay and its clay fraction. The absence of quartz and smaller particles of the clay fraction result in a comparatively lower temperature for structural consolidation associated with reduced open porosity. This can be attributed to solid state sintering alone, in contrast to a higher temperature liquid phase sintering needed for complete consolidation of the natural kaolinitic clay.
DOI: 10.6084/m9.figshare.10073477
title: Influence of Molybdenum on Microstructure and Pitting Corrosion Behavior of Solution-Treated Duplex Stainless Steel in a Lithium Chloride Solution

description: With technological advances in the several areas of knowledge, the constant search for materials with characteristics that meet certain applications has been growing, especially in the chemical and petrochemical industries, where materials capable of withstanding the conditions of corrosion in aggressive environments are required. The aim of this paper was to analyze the influence of the alloy element molybdenum on the microstructure and the resistance to corrosion of two duplex stainless steels identified as A (with molybdenum) and B (without molybdenum), after solution-treated under the following conditions: heating at 1100ºC for 30, 120 and 240 minutes. The steels were characterized by SEM, EDS, DRX and microhardness. The rise in solution treatment time fostered an increase in the volumetric fraction of the ferrite phase, in both steels. The solution treatment at 1100ºC for 120 minutes, for steels A and B, provided good resistance to pit corrosion, as well as the development of a passivating film in the solution of lithium chloride (120,000 ppm of chloride ions).
DOI: 10.6084/m9.figshare.10073477.v1
title: Influence of Molybdenum on Microstructure and Pitting Corrosion Behavior of Solution-Treated Duplex Stainless Steel in a Lithium Chloride Solution

description: With technological advances in the several areas of knowledge, the constant search for materials with characteristics that meet certain applications has been growing, especially in the chemical and petrochemical industries, where materials capable of withstanding the conditions of corrosion in aggressive environments are required. The aim of this paper was to analyze the influence of the alloy element molybdenum on the microstructure and the resistance to corrosion of two duplex stainless steels identified as A (with molybdenum) and B (without molybdenum), after solution-treated under the following conditions: heating at 1100ºC for 30, 120 and 240 minutes. The steels were characterized by SEM, EDS, DRX and microhardness. The rise in solution treatment time fostered an increase in the volumetric fraction of the ferrite phase, in both steels. The solution treatment at 1100ºC for 120 minutes, for steels A and B, provided good resistance to pit corrosion, as well as the development of a passivating film in the solution of lithium chloride (120,000 ppm of chloride ions).