cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.12094980.v1
title: Influence of concretes compressive strength on superficial wettability

description: ABSTRACT Concrete surfaces are one of the substrates on which the mortar coating, widely used in buildings, can be applied. Frequently, when there are incompatibilities between the substrate and the mortar, the coating system’s durability can be compromised, causing pathological manifestations such as detachments and displacements. To reach a better mortar coating adhesion and adherence, would be ideal that the substrate presents a hydrophilic surface, which allows a greater coating spreading. In this context, the present research aims to evaluate the superficial wettability of concretes with different compressive strength, in order to infer the performance from the point of view of adherence of a mortar coating layer on these substrates. Five concretes were dosed with different proportions and water/binder ratios, resulting in different values of compressive strength at 28 days. Concrete characterization in terms of compressive strength was done according to ABNT NBR 5739:2007, and water absorption by capillarity according to ABNT NBR 9779:2012. The concretes surface wetness test was evaluated through a sessile drop profile capture equipment. It was identified that the concretes compressive strenght has an influence on the wettability of its surfaces. Concretes with higher compressive strength have, beyond a lower absorption, a lower wettability. The mortar coating applied on a concrete substrate with higher compressive strength and lower capillary porosity can result in a lower mortar paste absorption by substrate pores and a lower contact extension, hampering the development of the mechanical interlocking and the adherence between the materials.
DOI: 10.6084/m9.figshare.12094974
title: Corrosion of galvanic couplings of Ni-Cr and Co-Cr alloys with Ti-6Al-4V in artificial saliva using electrochemical methods

description: ABSTRACT In this work, the open-circuit corrosion potentials of the alloys studied in aerated artificial saliva were determined; in the same solution, the potentiodynamic polarization curves of said alloys have been drawn. The corrosion potentials and current intensities of the galvanic coupling of the Ti-6Al-4V alloy with the Co-Cr and Ni-Cr alloys were determined using the Evans method, finding that the galvanic couples more resistant to corrosion in the electrolytic medium considered are those formed between the Ti alloy and the Co-Cr alloys; the least resistant are those formed between Ti alloy and Ni-Cr alloys. The corroded surfaces of the seven alloys considered in this work were also studied, and by EDAX the corrosion products due to the ions detached in the electrolytic medium were analyzed.
DOI: 10.6084/m9.figshare.12094974.v1
title: Corrosion of galvanic couplings of Ni-Cr and Co-Cr alloys with Ti-6Al-4V in artificial saliva using electrochemical methods

description: ABSTRACT In this work, the open-circuit corrosion potentials of the alloys studied in aerated artificial saliva were determined; in the same solution, the potentiodynamic polarization curves of said alloys have been drawn. The corrosion potentials and current intensities of the galvanic coupling of the Ti-6Al-4V alloy with the Co-Cr and Ni-Cr alloys were determined using the Evans method, finding that the galvanic couples more resistant to corrosion in the electrolytic medium considered are those formed between the Ti alloy and the Co-Cr alloys; the least resistant are those formed between Ti alloy and Ni-Cr alloys. The corroded surfaces of the seven alloys considered in this work were also studied, and by EDAX the corrosion products due to the ions detached in the electrolytic medium were analyzed.
DOI: 10.6084/m9.figshare.12094956
title: Evaluation of erosive and abrasive wear resistance of the WC 12Co coatings applied HVOF thermal spray

description: ABSTRACT Coatings are applied in order to extend the life of components operating in harsh environments. Metal-ceramic coatings known as cermet, such as WC-Co, consist of tungsten carbides immersed in a cobalt matrix and are used as wear-resistant materials. The HVOF (High Velocity Oxygen Fuel) spraying process is most suitable when one wants to obtain carbide coatings. The HVOF thermal spray presents excellent quality coatings with respect to porosity, hardness, strength, density, roughness and adhesion to the substrate. The present study investigates and compares the erosive and abrasive wear resistance of coatings obtained by HVOF, applied on AISI 1020 steel substrates. Were performed erosion tests using a specific tribometer, abrasion test according to ASTM G65-16, scanning electron microscope (SEM), microhardness and roughness of the coatings. The materials used were WC 12Co alloys. As a result of the erosive wear test, the coating has proved to be a good choice when dealing with resistance at lower angles of incidence. In the first hour of testing, erosion rate was 42% higher at 90° angle than at 30° impact angle. In the abrasive wear test, the result of the volumetric wear can be observed in the micrographs after the test, noting that there was a removal of carbides from the surface of the coating, resulting in wear, in which the samples had a volumetric loss of 2.68 ± 0.28 mm³. Such results indicate the WC 12Co material a good choice when it comes to wear resistance for protection of industrial mechanical components that suffer wear.
DOI: 10.25345/c5vr5r
title: MassIVE MSV000087105 - Mavel_Bitar_JPBA_2017_ESI_Pos-2-Autism_Urinary
title: J Pharm Biomed Anal. 2018 Apr 15;152:57-65. doi: 10.1016/j.jpba.2018.01.007. Identification of metabolic pathway disturbances using multimodal metabolomics in autistic disorders in a Middle Eastern population
DOI: 10.6084/m9.figshare.12094956.v1
title: Evaluation of erosive and abrasive wear resistance of the WC 12Co coatings applied HVOF thermal spray

description: ABSTRACT Coatings are applied in order to extend the life of components operating in harsh environments. Metal-ceramic coatings known as cermet, such as WC-Co, consist of tungsten carbides immersed in a cobalt matrix and are used as wear-resistant materials. The HVOF (High Velocity Oxygen Fuel) spraying process is most suitable when one wants to obtain carbide coatings. The HVOF thermal spray presents excellent quality coatings with respect to porosity, hardness, strength, density, roughness and adhesion to the substrate. The present study investigates and compares the erosive and abrasive wear resistance of coatings obtained by HVOF, applied on AISI 1020 steel substrates. Were performed erosion tests using a specific tribometer, abrasion test according to ASTM G65-16, scanning electron microscope (SEM), microhardness and roughness of the coatings. The materials used were WC 12Co alloys. As a result of the erosive wear test, the coating has proved to be a good choice when dealing with resistance at lower angles of incidence. In the first hour of testing, erosion rate was 42% higher at 90° angle than at 30° impact angle. In the abrasive wear test, the result of the volumetric wear can be observed in the micrographs after the test, noting that there was a removal of carbides from the surface of the coating, resulting in wear, in which the samples had a volumetric loss of 2.68 ± 0.28 mm³. Such results indicate the WC 12Co material a good choice when it comes to wear resistance for protection of industrial mechanical components that suffer wear.
DOI: 10.6084/m9.figshare.12094986
title: Effect of the addition of glasses as sintering aids on microstructure and properties of nanoalumina

description: ABSTRACT Alumina-Glass compositions were prepared to evaluate the effect of glass as sintering aids. The composites showed densification below 1100°C. The highest density values (~95%) were obtained for compositions based respectively on borosilicate (G2 and G3) and soda lime glasses (G4), all [A1] [A2] containing Na in the precursor powder. Samples G1 (K-based) and G5 (no K or Na in the precursor glass powder) presented irregular morphology with the presence of intergranular porosity. The composition G2, G3, and G4 presented uniform morphology corresponding to higher densification.
DOI: 10.6084/m9.figshare.12094986.v1
title: Effect of the addition of glasses as sintering aids on microstructure and properties of nanoalumina

description: ABSTRACT Alumina-Glass compositions were prepared to evaluate the effect of glass as sintering aids. The composites showed densification below 1100°C. The highest density values (~95%) were obtained for compositions based respectively on borosilicate (G2 and G3) and soda lime glasses (G4), all [A1] [A2] containing Na in the precursor powder. Samples G1 (K-based) and G5 (no K or Na in the precursor glass powder) presented irregular morphology with the presence of intergranular porosity. The composition G2, G3, and G4 presented uniform morphology corresponding to higher densification.
DOI: 10.6084/m9.figshare.12094983.v1
title: Structural quality in single crystalline CdSe ingots grown by PVT

description: ABSTRACT CdSe is II-VI semiconductor with compact hexagonal structure. It has a band gap of 1.82 eV and a high stopping power for nuclear radiation. Single crystalline CdSe ingots were grown by Physical Vapor Transport (PVT) employing a horizontal reactor. As devices critically depend on material properties its single crystalline quality was determined by chemical etching and transmission electron microscopy. Results were compared to those corresponding to Bridgman High Pressure (HPB) grown material and also to PVT material grown in a vertical reactor.
DOI: 10.6084/m9.figshare.12094983
title: Structural quality in single crystalline CdSe ingots grown by PVT

description: ABSTRACT CdSe is II-VI semiconductor with compact hexagonal structure. It has a band gap of 1.82 eV and a high stopping power for nuclear radiation. Single crystalline CdSe ingots were grown by Physical Vapor Transport (PVT) employing a horizontal reactor. As devices critically depend on material properties its single crystalline quality was determined by chemical etching and transmission electron microscopy. Results were compared to those corresponding to Bridgman High Pressure (HPB) grown material and also to PVT material grown in a vertical reactor.
DOI: 10.6084/m9.figshare.12095001
title: Partial replacement of CPV-ARI cement by water treatment plant sludge (WTS)

description: ABSTRACT The sludge generated during the water treatment process to supply the population is most often improperly disposed of in the water bodies, causing negative environmental impacts. In this context, the present study aimed at the valorization of the water treatment plant sludge (ETA) through its incorporation in Portland cement. The methodology consisted of producing of Portland cement pastes (CP V-ARI) containing ETA sludge in substitution contents of 0, 10 and 20%. Mechanical strength and hydrated compounds were evaluated by XRD, TG / DTG and SEM tests, as well as conduction calorimetry. Replacing CPV-ARI cement by ETA sludge reduced compressive strength, especially at 7 days. It was possible to observe a higher formation of ettringite in the samples containing ETA sludge, which probably negatively influenced the mechanical behavior. However, the incorporation of the compounds present in the ETA sludge in the cementitious matrix was observed, showing that the use of ETA sludge in Portland cement may indicate a safe alternative for its final destination.
DOI: 10.6084/m9.figshare.12095001.v1
title: Partial replacement of CPV-ARI cement by water treatment plant sludge (WTS)

description: ABSTRACT The sludge generated during the water treatment process to supply the population is most often improperly disposed of in the water bodies, causing negative environmental impacts. In this context, the present study aimed at the valorization of the water treatment plant sludge (ETA) through its incorporation in Portland cement. The methodology consisted of producing of Portland cement pastes (CP V-ARI) containing ETA sludge in substitution contents of 0, 10 and 20%. Mechanical strength and hydrated compounds were evaluated by XRD, TG / DTG and SEM tests, as well as conduction calorimetry. Replacing CPV-ARI cement by ETA sludge reduced compressive strength, especially at 7 days. It was possible to observe a higher formation of ettringite in the samples containing ETA sludge, which probably negatively influenced the mechanical behavior. However, the incorporation of the compounds present in the ETA sludge in the cementitious matrix was observed, showing that the use of ETA sludge in Portland cement may indicate a safe alternative for its final destination.
DOI: 10.6084/m9.figshare.12094977
title: Comparative analysis of solid state hydroxyapatite synthesis

description: ABSTRACT Hydroxyapatite is a calcium phosphate considered a biomaterial used in bone restorations, since it has characteristics similar to the mineral phase of bone tissue. Due to its many methods of production, the synthesis of hydroxyapatite powder has stimulated interest of academic research and industries, as the conditions of synthesis and reagents influence the structure, morphology and application of the desired final compound. This work aims to perform a comparative study on hydroxyapatite powder synthesis using equal reagents by two different methods: mechanochemical and calcination. The synthesis of hydroxyapatite was performed by solid state reaction using as precursors, calcium hydroxide and calcium monoacid phosphate in stoichiometric quantities. The characterizations were performed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, dispersive energy spectroscopy, density, porosity and Vickers microhardness. X-ray diffractograms showed a single phase for the mechanochemical method and more than one phase for the calcination method, the phases were confirmed after refinement by the Rietveld method and the average crystallite size was calculated by the Scherrer equation. Raman spectroscopy showed bands of the vibrational modes of hydroxyapatite. The micrographs characterized the morphological differences in the samples due to different synthesis methods and the dispersive energy spectroscopy indicated the calcium/phosphorus ratios of the samples, classifying it as calcium phosphate-based ceramic. Measurements of sample densities and porosities were performed using the pycnometer method based on the Archimedes principle. The values found were satisfactory, since they are close to theoretical values found in the literature. Vickers microhardness measurements were obtained in the samples, in order to verify their mechanical properties. The methods employed proved to be effective in the production of hydroxyapatite powders.
DOI: 10.6084/m9.figshare.12094977.v1
title: Comparative analysis of solid state hydroxyapatite synthesis

description: ABSTRACT Hydroxyapatite is a calcium phosphate considered a biomaterial used in bone restorations, since it has characteristics similar to the mineral phase of bone tissue. Due to its many methods of production, the synthesis of hydroxyapatite powder has stimulated interest of academic research and industries, as the conditions of synthesis and reagents influence the structure, morphology and application of the desired final compound. This work aims to perform a comparative study on hydroxyapatite powder synthesis using equal reagents by two different methods: mechanochemical and calcination. The synthesis of hydroxyapatite was performed by solid state reaction using as precursors, calcium hydroxide and calcium monoacid phosphate in stoichiometric quantities. The characterizations were performed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, dispersive energy spectroscopy, density, porosity and Vickers microhardness. X-ray diffractograms showed a single phase for the mechanochemical method and more than one phase for the calcination method, the phases were confirmed after refinement by the Rietveld method and the average crystallite size was calculated by the Scherrer equation. Raman spectroscopy showed bands of the vibrational modes of hydroxyapatite. The micrographs characterized the morphological differences in the samples due to different synthesis methods and the dispersive energy spectroscopy indicated the calcium/phosphorus ratios of the samples, classifying it as calcium phosphate-based ceramic. Measurements of sample densities and porosities were performed using the pycnometer method based on the Archimedes principle. The values found were satisfactory, since they are close to theoretical values found in the literature. Vickers microhardness measurements were obtained in the samples, in order to verify their mechanical properties. The methods employed proved to be effective in the production of hydroxyapatite powders.
DOI: 10.6084/m9.figshare.12094992
title: Green synthesis of zinc oxide nanoparticles

description: ABSTRACT The interest in the synthesis of nanoparticles using plant extracts has been growing in recent decades due to the non-generation of toxic chemical residues and bland synthesis conditions. Brazil is one of the leaders in planted forests, mainly of the genus Eucalyptus, because of this the objective of this work was to synthesize nanoparticles of zinc oxide using ethanolic extract of the leaves of Eucalyptus dunnii. The leaves were dried and ground to obtain powder, 10 g of this was added in 100 ml of ethyl alcohol, the solution was kept in a water bath at 80 °C for 75 min, the solution was filtered to obtain the extract. For the synthesis 20 mL of extract and 1.57 g of zinc acetate were used, the solution was maintained at 80 ºC under vigorous magnetic stirring for 20 min, after which the heat treatment was carried out in a muffle at 500 ºC for 2 h. The obtained nanoparticles presented crystalline characteristic and average diameter of 32,24 nm. The FTIR spectrum of the extract showed several peaks related to reducing compounds capable of performing the synthesis, while the spectrum of the nanoparticles showed that even after calcination, the presence of organic compounds that can be responsible for their stabilization is still detected. Thus, the ethanolic extract of E. dunnii has a reducing capacity to perform the synthesis of crystalline na-noparticles of zinc oxide.
DOI: 10.6084/m9.figshare.12094962
title: An Overview of Laser Engineered Net Shaping of Ceramics

description: ABSTRACT Additive manufacturing (AM) has provided huge versatility in geometry and materials, allowing new products and processes in several areas to be created. Laser Engineered Net Shaping (LENS) is an additive manufacturing process created in 1995 that allows building high-density metals and ceramics parts with no need for further operation. This manuscript aims to study the scientific literature about the process of Laser Engineered Net Shaping related to ceramics. After a systematic review, the articles were grouped into three categories: ceramic coating and AM of ceramics and AM of composites with ceramic reinforcement. Raw materials, substrates, applications, process parameters, and the obtained properties were analyzed and summarized for each group. Most of the additive manufacturing of ceramic parts are related to alumina, which present similar properties when compared to the traditionally manufactured ones. Recent works have the aid of an ultrasonic vibration to homogenize the in-process material, reduce cracks and improve mechanical properties. The additive manufacturing of composites with ceramic reinforcement has been used to create functionally graded composites materials with increased hardness, while the ceramic coating has been employed to manufacture biocompatible coating with increased hardness and low wear rate. Moreover, an additive manufacturing timeline including Laser Engineered Net Shaping landmarks is presented.
DOI: 10.6084/m9.figshare.12094959
title: Synthesis and characterization of natural hydroxyapatite extracted from pirarucu scales (Arapaima gigas)articles

description: ABSTRACT The hydroxyapatite belongs to the group of ceramic biomaterials being applied in the medical area due to its biocompatibility and osteoconductive properties, which makes it an option for treatments involving recovery of bone traumas. Fishing residues, bones and scales can be used as an inexpensive source for the production of calcium phosphates (hydroxyapatite). The objective of the study was the use of the non-toxic residue pirarucu scales to investigate the viability of extracting natural hydroxyapatite and characterizing it by physico-chemical and structural analyzes in order to prove its integrity. Firstly, thermal characterization was performed to establish the conditions of the heat treatment. With this, the scales were heat treated for the removal of the organic compounds. Thereafter, the material was homogenized, sieved and purified with reagents, because the sample could absorb impurities during the experimental procedure. The physical-chemical and structural characterizations were performed to accompany and prove the stages developed and examined. The results showed that the product obtained showed 99% of natural HAp phase and crystalline powders. In the infrared region, the peaks 3750-3500 cm-1 and 610-560 cm-1 were obtained referring to the OH- and PO4-3 ions respectively, referring to the functional groups hydroxyl and phosphate that constitute the chemical formula of hydroxyapatite and, by means of dispersive energy spectroscopy, the samples presented elemental percentages of calcium (37%), oxygenus (40%) and phosphorus (13%) that are compatible with the Ca/P molar ratio of the hydroxyapatite phase.
DOI: 10.6084/m9.figshare.12094959.v1
title: Synthesis and characterization of natural hydroxyapatite extracted from pirarucu scales (Arapaima gigas)articles

description: ABSTRACT The hydroxyapatite belongs to the group of ceramic biomaterials being applied in the medical area due to its biocompatibility and osteoconductive properties, which makes it an option for treatments involving recovery of bone traumas. Fishing residues, bones and scales can be used as an inexpensive source for the production of calcium phosphates (hydroxyapatite). The objective of the study was the use of the non-toxic residue pirarucu scales to investigate the viability of extracting natural hydroxyapatite and characterizing it by physico-chemical and structural analyzes in order to prove its integrity. Firstly, thermal characterization was performed to establish the conditions of the heat treatment. With this, the scales were heat treated for the removal of the organic compounds. Thereafter, the material was homogenized, sieved and purified with reagents, because the sample could absorb impurities during the experimental procedure. The physical-chemical and structural characterizations were performed to accompany and prove the stages developed and examined. The results showed that the product obtained showed 99% of natural HAp phase and crystalline powders. In the infrared region, the peaks 3750-3500 cm-1 and 610-560 cm-1 were obtained referring to the OH- and PO4-3 ions respectively, referring to the functional groups hydroxyl and phosphate that constitute the chemical formula of hydroxyapatite and, by means of dispersive energy spectroscopy, the samples presented elemental percentages of calcium (37%), oxygenus (40%) and phosphorus (13%) that are compatible with the Ca/P molar ratio of the hydroxyapatite phase.