cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7453049
title: A comparative study between PETG and PLA for 3D Printing through thermal, chemical and mechanical characterization

description: ABSTRACT The extrusion-based 3D printing has become popular in recent years due to the emergence of open source projects and low-cost machines that have made the technology accessible to all levels of users. In parallel, new materials, in general thermoplastic filaments, are inserted in the market for application in this type of manufacturing technique, making it increasingly necessary to develop experimental characterization studies to provide technical data to users. Thus, we sought to study poly(ethylene terephthalate glycol) (PETG), a polymer of recent adoption in this context, and compare it to poly(lactic acid) (PLA), the most popular one in this field. Both materials were mechanically analyzed by traction through samples made by 3D printing varying the angles of deposition of the extruded material. The same type of analysis was made using parts built by injection molding, for comparison purposes. The materials in their initial filamentary state were thermally evaluated by TGA and DSC, and chemically evaluated by FTIR. The last two characterization techniques were also applied to the polymers after the injection and 3D printing processing. The results showed that the tensile mechanical properties of the printed components are strongly influenced by the orientation of the filaments deposited in the layers and by the mesostructure of the parts. PLA has mechanical superiority, greater maximum tension and high rigidity, in relation to PETG, in the injected and printed samples. PETG, in turn, has shown to be more resistant to thermal degradation, more thermally stable (because it does not show significant changes in its thermal behavior after being processed), and more flexible, which is very interesting for 3D printing applications. Finally, the molecular chemical structure of both polymers was similar to that described in other studies found in the literature and was slightly altered by the manufacturing processes.
DOI: 10.6084/m9.figshare.7453055.v1
title: Production of nanofibrillary suspensions of vegetable cellulose by means of a combined process - Energy expenditure evaluation

description: ABSTRACT The present study had as objective to produce vegetable cellulose nanofibrils with brown and bleached Kraft pulp by means of a pretreatment enzymatic and later a mechanical,known as combined process, with the purpose of decreased the energy waste. For this, cellulose pulp samples were previously destructured by water saturation and dismantled in a mechanical sheredder, after were stored under refrigeration at 5 ° C. For the enzymatic pretreatment, it was used the commercial enzyme Cellic CTec2, in percentages ranging from 0.01 to 0.1% in a controlled hydrolysis with neutral pH, at ambient temperature for one hour, being that the 0.01% amount samples underwent 1 and 2 hors enzymatic hydrolysis. After the time of hydrolysis, the pulp was passed in a disk mill, where in this process the consumption of the energy was measured with the aid of an energy meter. For the production of the gel, the pulps were processed by the disk mill passages cycles. For enzymatic inhibition the contents ewere heated to 85 ° C. The gels were stored at 5 ° C. The process was characterized by the measure energy expenditure for each sample and its controls, in addition to measuring the yield of each gel produced. According to the results the combined process was feasible for the production
DOI: 10.6084/m9.figshare.7453046
title: Enhancing the sugars production yieldby supporting H3PW12O40 heteropoly acid on activated carbon for use as catalyst in hydrolysis of cellulose

description: ABSTRACT In this work, two catalysts were produced to be used in hydrolysis of cellulose reactions to obtain glucose, a raw material used in the production of bioethanol. The heteropoly acid, H3PW12O40 (HPW), reported as strong and thermally stable acid, was supported on activated carbon (AC) in a ratio varying from 1:1 to 2:1 to produce the catalysts AC-HPW (1:1) and AC-HPW (2:1). The catalysts were tested in cellulose hydrolysis evaluating some reaction variables and the results show the remarkable dependence of reaction temperature, amount and acidity of the catalyst. The results indicate the advantage of supporting HPW on carbonaceous material for using as catalyst in hydrolysis of cellulose, showing better conversion rate into sugars comparing with unsupported HPW.
DOI: 10.7284/101684
title: ADCP (Acoustic Doppler Current Profiler) data collected during research cruise MV0906 using a Hawaii UHDAS instrument system onboard the platform RV Melville

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7453043
title: Mineral composites reinforced with wood and tire rubber

description: ABSTRACT The objective of this research was to evaluate the potential of Eucalyptus grandis wood and rubber tire particles in the production of cement-wood panels. Eucalyptus grandis wood, 8 years old, was obtained from Companhia Mineira de Metais, located in the city of Paracatu -MG. For the formation of the panels, high initial strength CPV-ARI/Plus Portland cement was used as mineral binder and calcium chloride (CaCl2) as a cement cure accelerator. The panels were produced with the following parameters: dimensions of 48,0 x 48,0 x 1,5 cm, nominal density of 1,2 g / cm3, relation wood: cement (1:2.5) and water: cement ratio (1:1.5). The panels were pressed at a specific pressure of 4 MPa, at room temperature, 24 hour pressing/stapling time, and 28 day maturation time. The analysis of the results obtained, in relation to the minimum requirements of conventional panels produced by the Bison process, allows to affirm that: (1) for the physical properties of apparent density, water absorption and swelling in thickness all the treatments met the specifications; (2) for the mechanical properties of internal bonding and modulus of rupture in the static bending test, all treatments met the specifications; (3) for compression and modulus of elasticity in the static bending test, none of the treatments presented values compatible with the bison process.
DOI: 10.6084/m9.figshare.7453049.v1
title: A comparative study between PETG and PLA for 3D Printing through thermal, chemical and mechanical characterization

description: ABSTRACT The extrusion-based 3D printing has become popular in recent years due to the emergence of open source projects and low-cost machines that have made the technology accessible to all levels of users. In parallel, new materials, in general thermoplastic filaments, are inserted in the market for application in this type of manufacturing technique, making it increasingly necessary to develop experimental characterization studies to provide technical data to users. Thus, we sought to study poly(ethylene terephthalate glycol) (PETG), a polymer of recent adoption in this context, and compare it to poly(lactic acid) (PLA), the most popular one in this field. Both materials were mechanically analyzed by traction through samples made by 3D printing varying the angles of deposition of the extruded material. The same type of analysis was made using parts built by injection molding, for comparison purposes. The materials in their initial filamentary state were thermally evaluated by TGA and DSC, and chemically evaluated by FTIR. The last two characterization techniques were also applied to the polymers after the injection and 3D printing processing. The results showed that the tensile mechanical properties of the printed components are strongly influenced by the orientation of the filaments deposited in the layers and by the mesostructure of the parts. PLA has mechanical superiority, greater maximum tension and high rigidity, in relation to PETG, in the injected and printed samples. PETG, in turn, has shown to be more resistant to thermal degradation, more thermally stable (because it does not show significant changes in its thermal behavior after being processed), and more flexible, which is very interesting for 3D printing applications. Finally, the molecular chemical structure of both polymers was similar to that described in other studies found in the literature and was slightly altered by the manufacturing processes.
DOI: 10.6084/m9.figshare.7453043.v1
title: Mineral composites reinforced with wood and tire rubber

description: ABSTRACT The objective of this research was to evaluate the potential of Eucalyptus grandis wood and rubber tire particles in the production of cement-wood panels. Eucalyptus grandis wood, 8 years old, was obtained from Companhia Mineira de Metais, located in the city of Paracatu -MG. For the formation of the panels, high initial strength CPV-ARI/Plus Portland cement was used as mineral binder and calcium chloride (CaCl2) as a cement cure accelerator. The panels were produced with the following parameters: dimensions of 48,0 x 48,0 x 1,5 cm, nominal density of 1,2 g / cm3, relation wood: cement (1:2.5) and water: cement ratio (1:1.5). The panels were pressed at a specific pressure of 4 MPa, at room temperature, 24 hour pressing/stapling time, and 28 day maturation time. The analysis of the results obtained, in relation to the minimum requirements of conventional panels produced by the Bison process, allows to affirm that: (1) for the physical properties of apparent density, water absorption and swelling in thickness all the treatments met the specifications; (2) for the mechanical properties of internal bonding and modulus of rupture in the static bending test, all treatments met the specifications; (3) for compression and modulus of elasticity in the static bending test, none of the treatments presented values compatible with the bison process.
DOI: 10.6084/m9.figshare.7453046.v1
title: Enhancing the sugars production yieldby supporting H3PW12O40 heteropoly acid on activated carbon for use as catalyst in hydrolysis of cellulose

description: ABSTRACT In this work, two catalysts were produced to be used in hydrolysis of cellulose reactions to obtain glucose, a raw material used in the production of bioethanol. The heteropoly acid, H3PW12O40 (HPW), reported as strong and thermally stable acid, was supported on activated carbon (AC) in a ratio varying from 1:1 to 2:1 to produce the catalysts AC-HPW (1:1) and AC-HPW (2:1). The catalysts were tested in cellulose hydrolysis evaluating some reaction variables and the results show the remarkable dependence of reaction temperature, amount and acidity of the catalyst. The results indicate the advantage of supporting HPW on carbonaceous material for using as catalyst in hydrolysis of cellulose, showing better conversion rate into sugars comparing with unsupported HPW.
DOI: 10.6084/m9.figshare.7453034
title: Construction and validation of a distance Basic Life Support Course

description: ABSTRACT Objective: to describe the content construction and validation process of the Distance Education Basic Life Support Course. Method: methodological study, developed through literature review, outlined in the light of the Bloom's Taxonomy and Ausubel's Meaningful Learning Theory. For validation, the analysis was performed with judges, using a structured tool. Results: the construction of the distance course was complex and challenging, since it was tried to develop it with logical-methodological coherence, considering the constructivist perspective, representing an advance in the process of dissemination of the Urgency and Emergency teaching culture. As for the content validation process, it was verified that of the 16 suggestions made by the judges, 14 were accepted and two rejected. Conclusion: the course had its contents validated by experts.
DOI: 10.6084/m9.figshare.7453037
title: Biodegradation in simulated soil of HDPE/pro-oxidant/rice husk composites: application in agricultural tubes

description: ABSTRACT The use of agricultural waste, such as rice husk (RH), for the production of cheap and eco-friendly polymer composites has emerged as a promising field of interest. The aim of this work was the preparation of highdensity polyethylene (HDPE)-based composites reinforced with rice husk and an organic pro-oxidant (EG15) for the production of seedlings tubes. Photodegradation and degradation tests in simulated soil were performed for 90 and 180 days in order to study the decomposition of these composites. The SEM and OM images suggest that degradation of the composites samples was more extensive than the pure HDPE samples, probably because the composites present intense light absorption in the UV range, facilitating the degradation process even before biodegradation begins. In addition, after introducing RH particles in the polymeric matrix, the mechanical tensile and flexural properties, experienced significant changes, suggesting that the RH particles were homogeneously dispersed throughout the polymer matrix. Finally, the results have demonstrated that HDPE, RH, and EG15 are attractive materials for the design of polymeric composites for the production of seedlings tubes with excellent mechanical properties, being also easily decomposed in the environment once discarded.
DOI: 10.6084/m9.figshare.7453040
title: Mechanical and thermal properties of UHMWPE / LLDPE / CNT blends and nanocomposites for ballistic application

description: ABSTRACT The purpose of developing UHMWPE/ LLDPE/ CNT nanocomposite plates is to obtain a material that can be applied in laminated ceramic/polymer structures for high-impact ballistic protection. The polymer nanocomposite is used in the backing plate of the armor structure to absorb the residual kinetic energy of the projectile and shards from the ceramic material after impact. The polymer nanocomposite must have high fracture toughness, high mechanical strength and controlled deformation, in order to comply with these requirements. For instance, extreme deformations of the backing plate may cause injury to users of ballistic protective vests. In this work, a blend of linear low-density polyethylene (LLDPE) and ultra-high molecular weight polyethylene (UHMWPE) was prepared, using a high-rotation homogenizer with subsequent hot pressing, in order to facilitate the manufacturing process of the polymer nanocomposite plates. Furthermore, carbon nanotubes (0.5, 1.0 and 2.0 wt%), functionalized with nitric acid, were added to the polymer blend, in order to improve the mechanical properties of the resulting material. The mechanical and thermal properties of the polymer blend and the polymer nanocomposite were compared with each other. The polymer blends and polymer nanocomposites were submitted to mechanical tests such as Shore D hardness and uniaxial tensile tests. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were performed to evaluate thermal stability of the various compositions. Finally, scanning electron microscopy (SEM-FEG) was performed to evaluate the morphology of the nanocomposites.
DOI: 10.7284/100625
title: Expendable Probe data collected during research cruise MV0906 using a Sippican MK21 instrument system onboard the platform RV Melville

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7453034.v1
title: Construction and validation of a distance Basic Life Support Course

description: ABSTRACT Objective: to describe the content construction and validation process of the Distance Education Basic Life Support Course. Method: methodological study, developed through literature review, outlined in the light of the Bloom's Taxonomy and Ausubel's Meaningful Learning Theory. For validation, the analysis was performed with judges, using a structured tool. Results: the construction of the distance course was complex and challenging, since it was tried to develop it with logical-methodological coherence, considering the constructivist perspective, representing an advance in the process of dissemination of the Urgency and Emergency teaching culture. As for the content validation process, it was verified that of the 16 suggestions made by the judges, 14 were accepted and two rejected. Conclusion: the course had its contents validated by experts.
DOI: 10.6084/m9.figshare.7453037.v1
title: Biodegradation in simulated soil of HDPE/pro-oxidant/rice husk composites: application in agricultural tubes

description: ABSTRACT The use of agricultural waste, such as rice husk (RH), for the production of cheap and eco-friendly polymer composites has emerged as a promising field of interest. The aim of this work was the preparation of highdensity polyethylene (HDPE)-based composites reinforced with rice husk and an organic pro-oxidant (EG15) for the production of seedlings tubes. Photodegradation and degradation tests in simulated soil were performed for 90 and 180 days in order to study the decomposition of these composites. The SEM and OM images suggest that degradation of the composites samples was more extensive than the pure HDPE samples, probably because the composites present intense light absorption in the UV range, facilitating the degradation process even before biodegradation begins. In addition, after introducing RH particles in the polymeric matrix, the mechanical tensile and flexural properties, experienced significant changes, suggesting that the RH particles were homogeneously dispersed throughout the polymer matrix. Finally, the results have demonstrated that HDPE, RH, and EG15 are attractive materials for the design of polymeric composites for the production of seedlings tubes with excellent mechanical properties, being also easily decomposed in the environment once discarded.
DOI: 10.6084/m9.figshare.7453040.v1
title: Mechanical and thermal properties of UHMWPE / LLDPE / CNT blends and nanocomposites for ballistic application

description: ABSTRACT The purpose of developing UHMWPE/ LLDPE/ CNT nanocomposite plates is to obtain a material that can be applied in laminated ceramic/polymer structures for high-impact ballistic protection. The polymer nanocomposite is used in the backing plate of the armor structure to absorb the residual kinetic energy of the projectile and shards from the ceramic material after impact. The polymer nanocomposite must have high fracture toughness, high mechanical strength and controlled deformation, in order to comply with these requirements. For instance, extreme deformations of the backing plate may cause injury to users of ballistic protective vests. In this work, a blend of linear low-density polyethylene (LLDPE) and ultra-high molecular weight polyethylene (UHMWPE) was prepared, using a high-rotation homogenizer with subsequent hot pressing, in order to facilitate the manufacturing process of the polymer nanocomposite plates. Furthermore, carbon nanotubes (0.5, 1.0 and 2.0 wt%), functionalized with nitric acid, were added to the polymer blend, in order to improve the mechanical properties of the resulting material. The mechanical and thermal properties of the polymer blend and the polymer nanocomposite were compared with each other. The polymer blends and polymer nanocomposites were submitted to mechanical tests such as Shore D hardness and uniaxial tensile tests. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were performed to evaluate thermal stability of the various compositions. Finally, scanning electron microscopy (SEM-FEG) was performed to evaluate the morphology of the nanocomposites.
DOI: 10.6084/m9.figshare.7453025
title: Analisys of unstressed final-close vowels /e/ and /o/ in external vocalic sandhi in data of the NURC-Recife Project

description: ABSTRACT This study exams the behavior of close-mid vowels /e/ and /o/ in unstressed final position in three cases of external vocalic sandhi: degemination, elision and diphthongization. The material used for the analysis comes from one well-stablished corpus of Brazilian Portuguese: the NURC-Recife corpus. The results show that these close-mid vowels under examination are always pronounced as high vowels in unstressed final position. Besides, it is observed that when the context permits the occurrence of triggers elision or diphthongization, the close-mid vowels involved in these processes are preferably converted into glides (in 54,2% of the data), producing, with the following vowel, a rising diphthong. We also argue the possibility of juncture in the environment of final unstressed vowels followed by stressed vowel. However, this can only be observed when the stress and the rhythm patterns of the utterance are taken into consideration.
DOI: 10.6084/m9.figshare.7453028
title: Ammonium thiosulfate as blossom thinner in 'Maxi Gala' apple trees

description: Abstract: The objective of this work was to evaluate the feasibility of using ammonium thiosulfate as a chemical blossom thinner in 'Maxi Gala' apple (Malus domestica) trees and its effects on fruit quality. The experiment was carried out in an experimental orchard in the Southern Brazil, in a randomized complete block design, with five replicates. Ammonium thiosulfate was sprayed on the apple trees at the full bloom stage, at 0, 1.5, 2.5, and 3.5%. Evaluations were performed for the effects on crop load, fruit set, yield efficiency, and fruit quality parameters such as weight, shape, total soluble solids, seed number, flesh firmness, color, and russeting occurrence. Ammonium thiosulfate at 2.5% is effective to reduce crop load and to improve fruit quality. The thinning effect of ammonium thiosulfate is not dependent on the weather conditions during the crop season. The rate of 3.5% of ammonium thiosulfate causes overthinning and does not result in the improvement of fruit quality.
DOI: 10.6084/m9.figshare.7453028.v1
title: Ammonium thiosulfate as blossom thinner in 'Maxi Gala' apple trees

description: Abstract: The objective of this work was to evaluate the feasibility of using ammonium thiosulfate as a chemical blossom thinner in 'Maxi Gala' apple (Malus domestica) trees and its effects on fruit quality. The experiment was carried out in an experimental orchard in the Southern Brazil, in a randomized complete block design, with five replicates. Ammonium thiosulfate was sprayed on the apple trees at the full bloom stage, at 0, 1.5, 2.5, and 3.5%. Evaluations were performed for the effects on crop load, fruit set, yield efficiency, and fruit quality parameters such as weight, shape, total soluble solids, seed number, flesh firmness, color, and russeting occurrence. Ammonium thiosulfate at 2.5% is effective to reduce crop load and to improve fruit quality. The thinning effect of ammonium thiosulfate is not dependent on the weather conditions during the crop season. The rate of 3.5% of ammonium thiosulfate causes overthinning and does not result in the improvement of fruit quality.
DOI: 10.6084/m9.figshare.7453025.v1
title: Analisys of unstressed final-close vowels /e/ and /o/ in external vocalic sandhi in data of the NURC-Recife Project

description: ABSTRACT This study exams the behavior of close-mid vowels /e/ and /o/ in unstressed final position in three cases of external vocalic sandhi: degemination, elision and diphthongization. The material used for the analysis comes from one well-stablished corpus of Brazilian Portuguese: the NURC-Recife corpus. The results show that these close-mid vowels under examination are always pronounced as high vowels in unstressed final position. Besides, it is observed that when the context permits the occurrence of triggers elision or diphthongization, the close-mid vowels involved in these processes are preferably converted into glides (in 54,2% of the data), producing, with the following vowel, a rising diphthong. We also argue the possibility of juncture in the environment of final unstressed vowels followed by stressed vowel. However, this can only be observed when the stress and the rhythm patterns of the utterance are taken into consideration.
DOI: 10.7284/100626
title: GNSS (Global Navigation Satellite System) data collected during research cruise MV0906 using a Furuno GP-90D instrument system onboard the platform RV Melville

description: Original (unprocessed) data collected during a Field_expedition