cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14321685
title: Microstructure and Wear Properties of DIN 18MnCrSiMo6-4 Continuous Cooling Bainitic Steel Plasma Nitrided at Different Temperatures

description: ABSTRACT The new continuous cooling bainitic steels (CCBS) are an excellent alternative when high hardness, toughness and fatigue resistance are required. However, it is estimated that the wear rate of the CCBS is insufficient for application in highly mechanical loaded components, being necessary to improve the surface properties. The objective of this study is to analyze the effects of plasma nitriding on the microstructure and wear properties of DIN18MnCrSiMo6-4 continuous cooling bainitic steel. Therefore, treatments lasting 6 hours were conducted with a pressure of 3 mbar, a gas mixture composed of 76% N2 + 24% H2, and a temperature of 400, 450, 500 and 550 °C, respectively. The samples were analyzed by scanning electron microscopy, X-ray diffraction, microhardness and reciprocal sliding wear tests. Under the conditions investigated, it was possible to obtain a compound layer and to achieve an increase of up to 393% in surface hardness, however, the use of higher processing temperatures favored the extension of the depth layer. In all the nitrided samples, the major presence of ε-Fe2-3N nitrides phase was observed, and the γ'-Fe4N phase content was smaller. In the reciprocal sliding tests, there was a decrease in the wear of nitrided samples at temperature of 550 °C.
DOI: 10.6084/m9.figshare.14321685.v1
title: Microstructure and Wear Properties of DIN 18MnCrSiMo6-4 Continuous Cooling Bainitic Steel Plasma Nitrided at Different Temperatures

description: ABSTRACT The new continuous cooling bainitic steels (CCBS) are an excellent alternative when high hardness, toughness and fatigue resistance are required. However, it is estimated that the wear rate of the CCBS is insufficient for application in highly mechanical loaded components, being necessary to improve the surface properties. The objective of this study is to analyze the effects of plasma nitriding on the microstructure and wear properties of DIN18MnCrSiMo6-4 continuous cooling bainitic steel. Therefore, treatments lasting 6 hours were conducted with a pressure of 3 mbar, a gas mixture composed of 76% N2 + 24% H2, and a temperature of 400, 450, 500 and 550 °C, respectively. The samples were analyzed by scanning electron microscopy, X-ray diffraction, microhardness and reciprocal sliding wear tests. Under the conditions investigated, it was possible to obtain a compound layer and to achieve an increase of up to 393% in surface hardness, however, the use of higher processing temperatures favored the extension of the depth layer. In all the nitrided samples, the major presence of ε-Fe2-3N nitrides phase was observed, and the γ'-Fe4N phase content was smaller. In the reciprocal sliding tests, there was a decrease in the wear of nitrided samples at temperature of 550 °C.
DOI: 10.6084/m9.figshare.14321686.v1
title: Study of the performance of carbon steel AISI 1010 under the effect of epoxy/LDH-Zn-Al-NO2- coating barrier as corrosion inhibitor by electrochemical impedance spectroscopy

description: ABSTRACT To extend the useful life of power distribution and transmission lines metal artifacts, a hydrotalcite like nanomaterial has been studied because of its function as a nanocontainer for corrosion inhibition. The layered double hydroxides (LDH) are called hydrotalcite like material, wich are anion exchangers. Structurally, they consist of metal hydroxides with mixed positive charges separated by anionic and water molecules. Upon aggressive exposures, they can exchange ions with the environment, releasing a corrosion inhibition agent. In this research, three materials, (carbon steel 1010, carbon steel 1010 with epoxy resin and carbon steel 1010 with epoxy resin and the addition of 5% of LDH Zn-Al- NO2-) was analyzed by electrochemical impedance spectroscopy (EIS). The LDH was characterized by X-ray diffraction (XRD) and with Fourier transform infrared spectroscopy (FTIR). The results obtained evidenced the application of Zn-Al- NO2- in the elements of the power distribution and transmisson lines, since they did confered greater corrosion resistance to exposure and possible penetration of aggressive ions in the epoxy matrix (coating).
DOI: 10.6084/m9.figshare.14321686
title: Study of the performance of carbon steel AISI 1010 under the effect of epoxy/LDH-Zn-Al-NO2- coating barrier as corrosion inhibitor by electrochemical impedance spectroscopy

description: ABSTRACT To extend the useful life of power distribution and transmission lines metal artifacts, a hydrotalcite like nanomaterial has been studied because of its function as a nanocontainer for corrosion inhibition. The layered double hydroxides (LDH) are called hydrotalcite like material, wich are anion exchangers. Structurally, they consist of metal hydroxides with mixed positive charges separated by anionic and water molecules. Upon aggressive exposures, they can exchange ions with the environment, releasing a corrosion inhibition agent. In this research, three materials, (carbon steel 1010, carbon steel 1010 with epoxy resin and carbon steel 1010 with epoxy resin and the addition of 5% of LDH Zn-Al- NO2-) was analyzed by electrochemical impedance spectroscopy (EIS). The LDH was characterized by X-ray diffraction (XRD) and with Fourier transform infrared spectroscopy (FTIR). The results obtained evidenced the application of Zn-Al- NO2- in the elements of the power distribution and transmisson lines, since they did confered greater corrosion resistance to exposure and possible penetration of aggressive ions in the epoxy matrix (coating).
DOI: 10.5281/zenodo.4639506
title: Geometries for 'Linear-scaling implementation of multilevel Hartree-Fock theory'

description: Geometry files (.xyz format) used in the paper '<em>Linear-scaling implementation of multilevel Hartree-Fock theory</em>'
DOI: 10.6084/m9.figshare.14321688
title: Study of the tribological behavior of the Babbitt alloy – steel ABNT 1045 pair when varied thickness and roughness of the coating

description: ABSTRACT Babbitt, also known as patent metal or white metal, is a soft alloy widely used in sliding bearings that work in contact with steel, and has as base elements tin or lead, as well as intermetallic compounds usually formed by antimony and copper. The aim of this work was to evaluate the influence of the parameters roughness and thickness of the coating on the tribological behavior of the alloy when in contact with steel ABNT 1045. Tribological pin-on-disk tests were performed using ABNT 1045 steel pins and Babbitt-coated steel test specimens simulating the contact of a shaft on a Babbitt-coated bearing. The roughness and the thickness of the coating were varied in three levels, in order to observe the behavior in relation to the friction and the wear with the modification of these variables. In the tests that used test specimens with the smallest roughness within the analyzed range, an increase of 0.05 ± 0.02 to 0.46 ± 0.06 in the friction coefficient occurred when the coating thickness was raised from 0.45 ± 0.07 mm for 1.08 ± 0.17 mm. The highest coefficient of friction was observed in the test of the specimen with a higher coating thickness (1.08 ± 0.17 mm) and lower roughness (0.47 ± 0.01 μm), the highest wear was recorded in the test with the highest coating thickness and roughness (1.08 ± 0.17 mm and 1.29 ± 0.20 mm, respectively) and the lowest wear and friction coefficient were obtained by the test performed in the specimen with the least roughness (0.43 ± 0.03 μm) and medium coating thickness (0.45 ± 0.07 mm).
DOI: 10.6084/m9.figshare.14321688.v1
title: Study of the tribological behavior of the Babbitt alloy – steel ABNT 1045 pair when varied thickness and roughness of the coating

description: ABSTRACT Babbitt, also known as patent metal or white metal, is a soft alloy widely used in sliding bearings that work in contact with steel, and has as base elements tin or lead, as well as intermetallic compounds usually formed by antimony and copper. The aim of this work was to evaluate the influence of the parameters roughness and thickness of the coating on the tribological behavior of the alloy when in contact with steel ABNT 1045. Tribological pin-on-disk tests were performed using ABNT 1045 steel pins and Babbitt-coated steel test specimens simulating the contact of a shaft on a Babbitt-coated bearing. The roughness and the thickness of the coating were varied in three levels, in order to observe the behavior in relation to the friction and the wear with the modification of these variables. In the tests that used test specimens with the smallest roughness within the analyzed range, an increase of 0.05 ± 0.02 to 0.46 ± 0.06 in the friction coefficient occurred when the coating thickness was raised from 0.45 ± 0.07 mm for 1.08 ± 0.17 mm. The highest coefficient of friction was observed in the test of the specimen with a higher coating thickness (1.08 ± 0.17 mm) and lower roughness (0.47 ± 0.01 μm), the highest wear was recorded in the test with the highest coating thickness and roughness (1.08 ± 0.17 mm and 1.29 ± 0.20 mm, respectively) and the lowest wear and friction coefficient were obtained by the test performed in the specimen with the least roughness (0.43 ± 0.03 μm) and medium coating thickness (0.45 ± 0.07 mm).
DOI: 10.6084/m9.figshare.14321689
title: Study of the wettability and the corrosion protection of the hybrid silane (3-aminopropyl) triethoxysilane (APTES) and (3-glycidyloxypropyl) trimethoxysilane (GPTMS) film on galvannealed steel

description: ABSTRACT In this work, the wettability of the galvannealed surface pretreated with the hybrid silane APTES/GPTMS film was measured by sessile drop method. The coatings were applied on the substrate from dip-coating method and dried in an oven. The study followed an experimental factorial design, 3³, with contact angle as response. The corrosion resistance was evaluated by electrochemical techniques and the surface morphology was characterized by scanning electron microscopy. The wettability results showed the best condition for galvannealed steel pretreated with the hybrid silane film for 2:1 APTES:GPTMS ratio, 2% silane concentration and 150 min of hydrolysis time, because the result may be related to a higher rate of hydrolysis of the silanes that is influenced by both the functional group present and by the type and number of hydrolyzed groups, resulting consequently in a higher availability of silanol groups in solution, promoting a greater crosslinking of the film on the metallic substrate.
DOI: 10.6084/m9.figshare.14321689.v1
title: Study of the wettability and the corrosion protection of the hybrid silane (3-aminopropyl) triethoxysilane (APTES) and (3-glycidyloxypropyl) trimethoxysilane (GPTMS) film on galvannealed steel

description: ABSTRACT In this work, the wettability of the galvannealed surface pretreated with the hybrid silane APTES/GPTMS film was measured by sessile drop method. The coatings were applied on the substrate from dip-coating method and dried in an oven. The study followed an experimental factorial design, 3³, with contact angle as response. The corrosion resistance was evaluated by electrochemical techniques and the surface morphology was characterized by scanning electron microscopy. The wettability results showed the best condition for galvannealed steel pretreated with the hybrid silane film for 2:1 APTES:GPTMS ratio, 2% silane concentration and 150 min of hydrolysis time, because the result may be related to a higher rate of hydrolysis of the silanes that is influenced by both the functional group present and by the type and number of hydrolyzed groups, resulting consequently in a higher availability of silanol groups in solution, promoting a greater crosslinking of the film on the metallic substrate.
DOI: 10.6084/m9.figshare.14321691.v1
title: The inhibitory and comparative effects of Zn-Al layered double hydroxide microcontainers intercalated with benzotriazole and nitrite for corrosion protection coatings on AISI 1010 carbon steel

description: ABSTRACT The electrochemical impedance spectroscopy and the open circuit potential techniques were used to analyse coatings with layered double hydroxides intercalated with benzotriazole (BTA), nitrite (NO2), and a combination of the two. These materials were added 5% (m/m) to epoxy resin and applied on carbon steel surface as an anticorrosive system. The analyses were performed during 1000 h of salt spray chamber exposure. Morphology and particle distribution on the coatings were characterized by FEG-SEM. The LDH BTA formed a complex with zinc from the LDH layer and a phase based on ZnO/ZnOH, as shown by XRD analysis. This complex may have impaired the LDH-BTA- corrosion inhibition process, as it formed an undesired phase on Zn-Al layers. The LDH NO2- enhanced corrosion resistance, inducing formation of a passivating layer on the metal surface due to corrosion inhibitor release and chloride ion capture.
DOI: 10.6084/m9.figshare.14321691
title: The inhibitory and comparative effects of Zn-Al layered double hydroxide microcontainers intercalated with benzotriazole and nitrite for corrosion protection coatings on AISI 1010 carbon steel

description: ABSTRACT The electrochemical impedance spectroscopy and the open circuit potential techniques were used to analyse coatings with layered double hydroxides intercalated with benzotriazole (BTA), nitrite (NO2), and a combination of the two. These materials were added 5% (m/m) to epoxy resin and applied on carbon steel surface as an anticorrosive system. The analyses were performed during 1000 h of salt spray chamber exposure. Morphology and particle distribution on the coatings were characterized by FEG-SEM. The LDH BTA formed a complex with zinc from the LDH layer and a phase based on ZnO/ZnOH, as shown by XRD analysis. This complex may have impaired the LDH-BTA- corrosion inhibition process, as it formed an undesired phase on Zn-Al layers. The LDH NO2- enhanced corrosion resistance, inducing formation of a passivating layer on the metal surface due to corrosion inhibitor release and chloride ion capture.
DOI: 10.5281/zenodo.4639843
title: Supplemental Material to "Robust Query Processing for Linked Data Fragments"

description: Supplemental Material to the Experimental Result in "Robust Query Processing for Linked Data Fragments". The Materials include the raw experimental results as well as the queries used in the experiments.
DOI: 10.5281/zenodo.4639841
title: Supplemental Material to "Robust Query Processing for Linked Data Fragments"

description: Supplemental Material to the Experimental Result in "Robust Query Processing for Linked Data Fragments". The Materials include the raw experimental results as well as the queries used in the experiments.
DOI: 10.6084/m9.figshare.14321694.v1
title: Synthesis and study of structural, vibrational and thermal properties of the Cu2+ ion complexed L-threonine single crystal by slow solvent evaporation method

description: ABSTRACT Semi-organic crystals synthesis formed by amino acids and metals in recent years has gained more attention because the promising structural and vibrational properties these molecules. In this context, this work aimed the synthesis of Cu2+ ion complexed L-Threonine single crystal by solvent evaporation slow method as well the study of structural, vibrational and thermal promising properties. The material was obtained after 30 days at pH 5.8. Was verified by X-ray diffraction that the synthetized crystal has a monoclinic system with space group P21. Thermogravimetric analysis showed that the material is stable up 50 ° C, undergoing a phase transformation by the loss of water molecules in the unit cell. At 180 ° C the XRD together with the Le Bail method showed material acquires a new structural conformation, remaining in a monoclinic system and transiting to the symmetry group P121.
DOI: 10.6084/m9.figshare.14321694
title: Synthesis and study of structural, vibrational and thermal properties of the Cu2+ ion complexed L-threonine single crystal by slow solvent evaporation method

description: ABSTRACT Semi-organic crystals synthesis formed by amino acids and metals in recent years has gained more attention because the promising structural and vibrational properties these molecules. In this context, this work aimed the synthesis of Cu2+ ion complexed L-Threonine single crystal by solvent evaporation slow method as well the study of structural, vibrational and thermal promising properties. The material was obtained after 30 days at pH 5.8. Was verified by X-ray diffraction that the synthetized crystal has a monoclinic system with space group P21. Thermogravimetric analysis showed that the material is stable up 50 ° C, undergoing a phase transformation by the loss of water molecules in the unit cell. At 180 ° C the XRD together with the Le Bail method showed material acquires a new structural conformation, remaining in a monoclinic system and transiting to the symmetry group P121.
DOI: 10.6084/m9.figshare.14321695
title: Modeling and numerical analysis of roller burnishing of AISI 4140 steel

description: ABSTRACT Metallic components for engineering applications are often employed under the action of thermal and mechanical loads, which tend to reduce their lifespan. Mechanical surface treatments appear as an alternative capable of extending the service life of these materials. These processes act by plastically deforming the surface, increasing its surface hardness and inducing compressive residual stresses. The combination of these factors leads to an increase of the part lifespan because it diminishes the nucleation and propagation of cracks, which are responsible for material failure by fracture. Although surface treatment processes such as shot peening and laser shock peening are widely used to induce compressive stresses, roller burnishing not only induces compressive stress and increases surface hardness, but also promotes the reduction of surface roughness. In this work, two-dimensional numerical simulation using the Finite Element Method (FEM) method for roller burnishing the hardened ABNT 4140 (40 HRC) steel was performed, considering the tool a rigid element, while the part was assumed as elasto-plastic. Burnishing force and feed rate were selected as input parameters which influence on roughness and residual stress induction was investigated. Moreover, unlike other two-dimensional numerical models, the initial roughness of the part was introduced in order to assess its influence on the process. In addition to that, the numerical simulation occurs in the interval from one peak to the other, defined by the feed mark of the previous turning operation (0.2 mm). The HertzWin software was used to define the feed rate for each condition, which was based on the half contact width (b) obtained for each force separately. The numerical results suggest the reduction of roughness and the increase of compressive residual when the rolling force is increased and the feed rate is reduced.
DOI: 10.6084/m9.figshare.14321695.v1
title: Modeling and numerical analysis of roller burnishing of AISI 4140 steel

description: ABSTRACT Metallic components for engineering applications are often employed under the action of thermal and mechanical loads, which tend to reduce their lifespan. Mechanical surface treatments appear as an alternative capable of extending the service life of these materials. These processes act by plastically deforming the surface, increasing its surface hardness and inducing compressive residual stresses. The combination of these factors leads to an increase of the part lifespan because it diminishes the nucleation and propagation of cracks, which are responsible for material failure by fracture. Although surface treatment processes such as shot peening and laser shock peening are widely used to induce compressive stresses, roller burnishing not only induces compressive stress and increases surface hardness, but also promotes the reduction of surface roughness. In this work, two-dimensional numerical simulation using the Finite Element Method (FEM) method for roller burnishing the hardened ABNT 4140 (40 HRC) steel was performed, considering the tool a rigid element, while the part was assumed as elasto-plastic. Burnishing force and feed rate were selected as input parameters which influence on roughness and residual stress induction was investigated. Moreover, unlike other two-dimensional numerical models, the initial roughness of the part was introduced in order to assess its influence on the process. In addition to that, the numerical simulation occurs in the interval from one peak to the other, defined by the feed mark of the previous turning operation (0.2 mm). The HertzWin software was used to define the feed rate for each condition, which was based on the half contact width (b) obtained for each force separately. The numerical results suggest the reduction of roughness and the increase of compressive residual when the rolling force is increased and the feed rate is reduced.
DOI: 10.6084/m9.figshare.14321697
title: Anti-adhesion and antibacterial activity of silver nanoparticles and graphene oxide-silver nanoparticle composites

description: ABSTRACT The rise of nanotechnology has allowed the development of several inorganic nanoparticles with strong biocidal properties against bacteria, fungi, and viruses. Among them, silver nanoparticles (AgNPs) stand out as one of the most promising antimicrobial nanomaterials. Graphene oxide (GO) is another attractive nanomaterial with antimicrobial properties. Although the antimicrobial effect of AgNPs and GO is known, the development of hybrid materials of GO-AgNPs has considerable interest in various applications since they may exhibit synergistic bactericidal properties that exceed the yields of the individual components. The aims of this work were to evaluate the antimicrobial activity and anti-adhesion properties of AgNPs and GO-AgNPs nanocomposites for potential applications in antimicrobial coatings. The antimicrobial activity was tested by agar diffusion method. It was found that activity varied according to the synthesis procedure of the nanomaterials. Pseudomonas aeruginosa, Bacillus cereus and Kokuria rhizophila were the most susceptible strains. The nanocomposite GO- AgNPs synthetized using the ex-situ method exhibited the highest antibacterial activity against all the assayed strains. Similar results were obtained for bacterial adhesion inhibition tests. Thus, GO-AgNPs nanohybrids could be applied as antibacterial coatings to prevent bacterial biofilm development.
DOI: 10.6084/m9.figshare.14321697.v1
title: Anti-adhesion and antibacterial activity of silver nanoparticles and graphene oxide-silver nanoparticle composites

description: ABSTRACT The rise of nanotechnology has allowed the development of several inorganic nanoparticles with strong biocidal properties against bacteria, fungi, and viruses. Among them, silver nanoparticles (AgNPs) stand out as one of the most promising antimicrobial nanomaterials. Graphene oxide (GO) is another attractive nanomaterial with antimicrobial properties. Although the antimicrobial effect of AgNPs and GO is known, the development of hybrid materials of GO-AgNPs has considerable interest in various applications since they may exhibit synergistic bactericidal properties that exceed the yields of the individual components. The aims of this work were to evaluate the antimicrobial activity and anti-adhesion properties of AgNPs and GO-AgNPs nanocomposites for potential applications in antimicrobial coatings. The antimicrobial activity was tested by agar diffusion method. It was found that activity varied according to the synthesis procedure of the nanomaterials. Pseudomonas aeruginosa, Bacillus cereus and Kokuria rhizophila were the most susceptible strains. The nanocomposite GO- AgNPs synthetized using the ex-situ method exhibited the highest antibacterial activity against all the assayed strains. Similar results were obtained for bacterial adhesion inhibition tests. Thus, GO-AgNPs nanohybrids could be applied as antibacterial coatings to prevent bacterial biofilm development.