cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6858170.v1
title: Cotton and fiber quality in function of picker harvest speed

description: ABSTRACT Cotton price is determined by the quality of the fiber, which can be damaged at the time of harvest, in addition to quantitative losses of non-harvested plume. Therefore, this study aimed to analyse soil and plant losses, and the quality of cotton fiber in relation to five harvest speeds (5, 6, 7, 8, and 9 km h-1) in the spindle system (picker). The experiment was conducted in Lucas do Rio Verde, Mato Grosso, Brazil. A randomized complete block design was used on plots of 0.9 ha, with 20 plot, five speeds, and four blocks. The results showed that the studied speeds did not significantly influence losses on the soil and plant, or the quality of the cotton fiber; therefore, the highest speed may be recommended.
DOI: 10.6084/m9.figshare.6858167
title: Studies on the Growth Control of ZnO Nanostructures synthesized by the Chemical Method

description: ABSTRACT ZnO nanostructures were synthesized through a chemical method using different Zn precursors and hexamethylenetetramine (HMTA) at 90 °C. The effects of the reactants on the morphological evolution of ZnO nanorods were investigated. The samples were characterized by using XRD, SEM, EDX and BET. The hexagonal wurtzite phase of ZnO was confirmed by X-ray diffraction (XRD). The performed analysis indicated that different morphologies were obtained by changing the reactants.
DOI: 10.6084/m9.figshare.6858164
title: Synthesis of ordered mesoporous silica: determination of optimum conditions for template removal

description: ABSTRACT Ordered mesoporous silica was synthesized by the sol-gel process using tetraethoxysilane (TEOS) as silica source and hexadecyltrimethyl ammonium bromide (CTAB) as structure directing agent. Post-synthesis surfactant removal was conducted by two techniques: calcination, with progressive increases in temperature up to 550 ºC and solvent extraction using HCl /EtOH as extracting solution. In the last mentioned technique, a few experimental variables were changed such as the acid concentration, the volume of extracting solution, the reflux time and the solvent employed for washing. The samples were characterized by N2 adsorption, FTIR spectroscopy and SEM. Both the synthesis technique used and the procedures to remove template lead to MCM-41 type material. Template extraction by calcination results in materials having a surface area of 1100 m2/g. On the other hand, extraction with HCl/EtOH leads to decreases in surface area, attributed to occlusion of the pores with organic material. In both cases, monitoring surfactant traces in the samples was performed using FTIR.
DOI: 10.6084/m9.figshare.6858167.v1
title: Studies on the Growth Control of ZnO Nanostructures synthesized by the Chemical Method

description: ABSTRACT ZnO nanostructures were synthesized through a chemical method using different Zn precursors and hexamethylenetetramine (HMTA) at 90 °C. The effects of the reactants on the morphological evolution of ZnO nanorods were investigated. The samples were characterized by using XRD, SEM, EDX and BET. The hexagonal wurtzite phase of ZnO was confirmed by X-ray diffraction (XRD). The performed analysis indicated that different morphologies were obtained by changing the reactants.
DOI: 10.6084/m9.figshare.6858164.v1
title: Synthesis of ordered mesoporous silica: determination of optimum conditions for template removal

description: ABSTRACT Ordered mesoporous silica was synthesized by the sol-gel process using tetraethoxysilane (TEOS) as silica source and hexadecyltrimethyl ammonium bromide (CTAB) as structure directing agent. Post-synthesis surfactant removal was conducted by two techniques: calcination, with progressive increases in temperature up to 550 ºC and solvent extraction using HCl /EtOH as extracting solution. In the last mentioned technique, a few experimental variables were changed such as the acid concentration, the volume of extracting solution, the reflux time and the solvent employed for washing. The samples were characterized by N2 adsorption, FTIR spectroscopy and SEM. Both the synthesis technique used and the procedures to remove template lead to MCM-41 type material. Template extraction by calcination results in materials having a surface area of 1100 m2/g. On the other hand, extraction with HCl/EtOH leads to decreases in surface area, attributed to occlusion of the pores with organic material. In both cases, monitoring surfactant traces in the samples was performed using FTIR.
DOI: 10.6084/m9.figshare.6858161
title: Off-pump Coronary Artery Bypass Grafting in Moyamoya Disease: a Case Report

description: Abstract Moyamoya disease is a rare, idiopathic, progressive, occlusive disease of the internal carotid artery characterized by the development of collateral vasculature in the brain base. In patients with accompanying coronary artery disease, cardiopulmonary bypass posses a potential risk for perioperative cerebral ischemic complication. Herein, we report a 53-year-old male case of Moyamoya disease and coronary artery disease who was treated with off-pump coronary artery bypass grafting.
DOI: 10.6084/m9.figshare.6858158
title: La2NiMnO6 double perovskite nanostructure prepared by citrate route for supercapacitors

description: ABSTRACT In this paper, the study of double perovskite La2NiMnO6 as electrode material for supercapacitors is presented. The mixed oxide was prepared by citrate precursor route (CIT). The sample was calcined for 4 hours at 800 °C. The material was characterized by PXRD, SEM and FTIR spectroscopy. Cyclic voltammetry and galvanostatic charge/discharge measurements were used to study the capacitive behavior of the nanomaterial in alkaline and acid solutions. I/V profiles were obtained at varying the scan rates from 10 to 100 mV/s. The galvanostatic charge/discharge curves were recorded at different current density values in the 3-17 A/g range. The higher capacitance values were obtained in alkaline medium. Thus, a specific capacitance of 1681 F/g at a current density of 3 A/g, and a power and an energy specific of 2903 W/kg and 378 Wh/kg, were obtained in KOH. While in acid solution these values were 492 F/g, 3225 W/kg and 137 Wh/kg, respectively. These promising results promote the use of the double perovskites for electrode materials in supercapacitors.
DOI: 10.6084/m9.figshare.6858161.v1
title: Off-pump Coronary Artery Bypass Grafting in Moyamoya Disease: a Case Report

description: Abstract Moyamoya disease is a rare, idiopathic, progressive, occlusive disease of the internal carotid artery characterized by the development of collateral vasculature in the brain base. In patients with accompanying coronary artery disease, cardiopulmonary bypass posses a potential risk for perioperative cerebral ischemic complication. Herein, we report a 53-year-old male case of Moyamoya disease and coronary artery disease who was treated with off-pump coronary artery bypass grafting.
DOI: 10.6084/m9.figshare.6858155
title: Propiedades catalíticas de grafeno dopado con metales de transición

description: ABSTRACT In this work a study based on the Density Functional Theory of graphene sheets doped with atoms of Fe, Co and Ni is carried out. The functional PBE1PBE and the pseudopotentials LANL2DZ for the metal atoms, and the 6-31G ++ (d) bases for the carbon atoms were adopted. Three systems formed by the substitution of a carbon atom by one of Fe, Co and Ni, respectively, are analyzed. The energetic, electronic and chemical reactivity properties were studied, making a systematic comparison with a pure graphene sheet. In order to simulate the presence of the solvent in the systems under study, the SCRF = PCM (Self Consistent Reaction Field = Polarizable Continuum Model) was used. In addition, for each system the catalytic properties for O2 adsorption were determined. Our results indicate that the presence of metal heteroatoms and water as solvent modifies the chemical reactivity and the adsorption of dioxygen, which could be determinant on the catalytic properties of doped graphene. The nickel-doped graphene sheet results to be the most reactive and it is the one with the most favorable energy for the adsorption of oxygen.
DOI: 10.6084/m9.figshare.6858158.v1
title: La2NiMnO6 double perovskite nanostructure prepared by citrate route for supercapacitors

description: ABSTRACT In this paper, the study of double perovskite La2NiMnO6 as electrode material for supercapacitors is presented. The mixed oxide was prepared by citrate precursor route (CIT). The sample was calcined for 4 hours at 800 °C. The material was characterized by PXRD, SEM and FTIR spectroscopy. Cyclic voltammetry and galvanostatic charge/discharge measurements were used to study the capacitive behavior of the nanomaterial in alkaline and acid solutions. I/V profiles were obtained at varying the scan rates from 10 to 100 mV/s. The galvanostatic charge/discharge curves were recorded at different current density values in the 3-17 A/g range. The higher capacitance values were obtained in alkaline medium. Thus, a specific capacitance of 1681 F/g at a current density of 3 A/g, and a power and an energy specific of 2903 W/kg and 378 Wh/kg, were obtained in KOH. While in acid solution these values were 492 F/g, 3225 W/kg and 137 Wh/kg, respectively. These promising results promote the use of the double perovskites for electrode materials in supercapacitors.
DOI: 10.6084/m9.figshare.6858155.v1
title: Propiedades catalíticas de grafeno dopado con metales de transición

description: ABSTRACT In this work a study based on the Density Functional Theory of graphene sheets doped with atoms of Fe, Co and Ni is carried out. The functional PBE1PBE and the pseudopotentials LANL2DZ for the metal atoms, and the 6-31G ++ (d) bases for the carbon atoms were adopted. Three systems formed by the substitution of a carbon atom by one of Fe, Co and Ni, respectively, are analyzed. The energetic, electronic and chemical reactivity properties were studied, making a systematic comparison with a pure graphene sheet. In order to simulate the presence of the solvent in the systems under study, the SCRF = PCM (Self Consistent Reaction Field = Polarizable Continuum Model) was used. In addition, for each system the catalytic properties for O2 adsorption were determined. Our results indicate that the presence of metal heteroatoms and water as solvent modifies the chemical reactivity and the adsorption of dioxygen, which could be determinant on the catalytic properties of doped graphene. The nickel-doped graphene sheet results to be the most reactive and it is the one with the most favorable energy for the adsorption of oxygen.
DOI: 10.6084/m9.figshare.6858149
title: Effect of weld superpulse time on the microstructural evolution of a low carbon steels

description: ABSTRACT The Super Pulse arc type was developed to provide a solution to butt root pass beads in the semi-automatic welding process with gas protection (GMAW). Unlike standard pulse welding, the Super Pulse uses a sequence of different pulse waveforms to create a cord shape and appearance similar to the GTAW process. It uses higher amperage in the primary phase to improve penetration and low amperage in the second phase to reduce the heat input. Spray transfer is used in the primary phase to improve penetration and short arc in the secondary phase to cool the solder bath giving less heat transfer and less distortion to the base material. In the literature there is little information regarding the relationship between the Super Pulse variables and the microstructural characteristics of the deposited metal. The objective of this work was to evaluate the influence of the times of each phase in Super Pulse mode, on the geometric characteristics of the cord and the solidification in weld deposits of low carbon steels. For this purpose, strands should be welded on an IRAM - IAS U500 42 - F24 plate by varying the phase time of the Super Pulse. In cross sections, the geometry of the bead was determined and in longitudinal sections, the microstructure and the characteristics of the molten and affected areas were determined. Preliminary results showed that bead geometry and solidification were strongly influenced by pulse parameters.
DOI: 10.6084/m9.figshare.6858146
title: Corrosion characterization in superduplex stainless steel cladding

description: ABSTRACT Superduplex stainless steels have a dual structure constituted approximately by 50% of ferrite and 50 % of austenite. This fact produces a good combination of mechanical properties and corrosion resistance. Thanks to these features their use is growing, mainly in the industries of paper, chemical, gas and oil. Surfacing welding is used for the manufacture and / or repair of parts and equipment. The properties of the coating depend on its chemical composition and microstructure, which are defined by the dilution with the base metal and the welding process utilized. Therefore, in cladding welding, the control of the present phases in the microstructure is essential to ensure the required properties. The objective of this work was to study the effect of heat input and the amount of layers of superduplex stainless steel deposits on the chemical composition, microstructure, hardness and pitting corrosion resistance. Six cladding coupons were welded by semiautomatic arc welding process: 1 and 2 layers coupons were welded with low, medium and high heat input (modifying only the welding speed). Macro and microstructure was analyzed by optical and scanning electron microscopy and X-ray diffraction. The geometrical and chemical dilutions were determined. Also, Vickers microhardness and pitting corrosion resistance were measured.
DOI: 10.6084/m9.figshare.6858149.v1
title: Effect of weld superpulse time on the microstructural evolution of a low carbon steels

description: ABSTRACT The Super Pulse arc type was developed to provide a solution to butt root pass beads in the semi-automatic welding process with gas protection (GMAW). Unlike standard pulse welding, the Super Pulse uses a sequence of different pulse waveforms to create a cord shape and appearance similar to the GTAW process. It uses higher amperage in the primary phase to improve penetration and low amperage in the second phase to reduce the heat input. Spray transfer is used in the primary phase to improve penetration and short arc in the secondary phase to cool the solder bath giving less heat transfer and less distortion to the base material. In the literature there is little information regarding the relationship between the Super Pulse variables and the microstructural characteristics of the deposited metal. The objective of this work was to evaluate the influence of the times of each phase in Super Pulse mode, on the geometric characteristics of the cord and the solidification in weld deposits of low carbon steels. For this purpose, strands should be welded on an IRAM - IAS U500 42 - F24 plate by varying the phase time of the Super Pulse. In cross sections, the geometry of the bead was determined and in longitudinal sections, the microstructure and the characteristics of the molten and affected areas were determined. Preliminary results showed that bead geometry and solidification were strongly influenced by pulse parameters.
DOI: 10.6084/m9.figshare.6858143
title: Study of friction stir spot welding on AA6063 aluminium alloy used in the ship building industry

description: ABSTRACT Friction stir spot welding (FSSW) is a novel process of metal joining. In the present work, the authors analysed the possibility of using this process to solve current problems in shipbuilding industry regarding small vessels by replacing the current arc welding techniques with the aforementioned process. Numerical simulation was carried out by the multiple purpose solver framework for Finite Element Method with a novel modelling approach. The problem was solved using a coupled mechanics system of equations in an axisymmetric continuum where material velocities were calculated in three dimensions, coupled with pressure and thermal fields. The heat source was calculated as a consequence of internal friction dissipation only. Two boundary conditions were analysed, adiabatic and with heat dissipation. Experimental welding tests were performed using a milling machine. Comparison between numerical modelling results and experimental FSSW testing results was done and analysed in detail.
DOI: 10.6084/m9.figshare.6858146.v1
title: Corrosion characterization in superduplex stainless steel cladding

description: ABSTRACT Superduplex stainless steels have a dual structure constituted approximately by 50% of ferrite and 50 % of austenite. This fact produces a good combination of mechanical properties and corrosion resistance. Thanks to these features their use is growing, mainly in the industries of paper, chemical, gas and oil. Surfacing welding is used for the manufacture and / or repair of parts and equipment. The properties of the coating depend on its chemical composition and microstructure, which are defined by the dilution with the base metal and the welding process utilized. Therefore, in cladding welding, the control of the present phases in the microstructure is essential to ensure the required properties. The objective of this work was to study the effect of heat input and the amount of layers of superduplex stainless steel deposits on the chemical composition, microstructure, hardness and pitting corrosion resistance. Six cladding coupons were welded by semiautomatic arc welding process: 1 and 2 layers coupons were welded with low, medium and high heat input (modifying only the welding speed). Macro and microstructure was analyzed by optical and scanning electron microscopy and X-ray diffraction. The geometrical and chemical dilutions were determined. Also, Vickers microhardness and pitting corrosion resistance were measured.
DOI: 10.6084/m9.figshare.6858140
title: Effect of welding parameters on welded steel wire mesh

description: ABSTRACT Reinforced concrete is the most widely used material in construction industry. Generally concrete is reinforced with ribbed bars. In certain applications, it is desirable to use welded mesh and are used in most reinforced concrete structures (buildings, roads, tunnels and prefabricated components). Welded mesh are generally electrowelded (PW: Projection Welding), where the heat necessary to produce the joint is originated by the resistance that oppose the workpieces to the flow of electric current, under the action of mechanical pressure. This process presents various operational parameters which affect the quality of welded joints and the microstructural evolution that takes place during welding. IRAM-IAS U 500-06 standard establishes the requirements to be met by welded steel mesh. The aim of this work is to study the influence of process parameters on the microstructural evolution and mechanical properties of the joints of welded mesh. ATR 500 M ribbed wires of 4 mm in diameter were welded by PW with different welding parameters. The influence of the welding current, welding time, pressure and prewelded time were evaluated. On welded joints, it was characterized the macro and microstructure, microhardness profiles and pull tests were performed. Comparisons with commercial mesh were made and compliance with the requirements of that standard is verified. A strong effect of time and welding current is observed and optimized procedure was obtained.
DOI: 10.6084/m9.figshare.6858143.v1
title: Study of friction stir spot welding on AA6063 aluminium alloy used in the ship building industry

description: ABSTRACT Friction stir spot welding (FSSW) is a novel process of metal joining. In the present work, the authors analysed the possibility of using this process to solve current problems in shipbuilding industry regarding small vessels by replacing the current arc welding techniques with the aforementioned process. Numerical simulation was carried out by the multiple purpose solver framework for Finite Element Method with a novel modelling approach. The problem was solved using a coupled mechanics system of equations in an axisymmetric continuum where material velocities were calculated in three dimensions, coupled with pressure and thermal fields. The heat source was calculated as a consequence of internal friction dissipation only. Two boundary conditions were analysed, adiabatic and with heat dissipation. Experimental welding tests were performed using a milling machine. Comparison between numerical modelling results and experimental FSSW testing results was done and analysed in detail.
DOI: 10.6084/m9.figshare.6858137
title: Evolución microestructural in-situ a alta temperatura de depósitos de soldadura de aceros 9Cr con diferentes contenidos de boro

description: ABSTRACT New alloys have been developed for enhancing the performance of the equipment used in thermoelectric power generation industry. With the objective of increasing the creep resistance of these materials, changes in the content of some microalloying elements were carried out. Boron bearing in creep strength enhanced 9Cr steel (CSE9Cr) welds improved martensite stabilization through precipitates. Mechanical properties are achieved after post weld heat treatments (PWHT). In this work, microstructural evolution of samples subjected to hot tensile test (HTT) was studied by means of in-situ X-Ray Diffraction (XRD) to determine the effect of boron in CSE9Cr welds on their mechanical properties at elevated temperatures. All weld metal coupons were welded using two experimental flux-cored wires with two levels of boron (20 and 60 ppm). A single post weld heat treatment was applied to each composition. HTT at different temperatures and initial strain rate were performed while the microstructure evolution was monitoring by in-situ XRD. Mechanical properties and XRD microstructural parameters were correlated. HTT results were extrapolated using correlation theory HTT-Creep and Larson-Miller parameterization. It was found that the higher boron in the weld metal decreased the rate of strength loss at elevated temperatures.
DOI: 10.6084/m9.figshare.6858140.v1
title: Effect of welding parameters on welded steel wire mesh

description: ABSTRACT Reinforced concrete is the most widely used material in construction industry. Generally concrete is reinforced with ribbed bars. In certain applications, it is desirable to use welded mesh and are used in most reinforced concrete structures (buildings, roads, tunnels and prefabricated components). Welded mesh are generally electrowelded (PW: Projection Welding), where the heat necessary to produce the joint is originated by the resistance that oppose the workpieces to the flow of electric current, under the action of mechanical pressure. This process presents various operational parameters which affect the quality of welded joints and the microstructural evolution that takes place during welding. IRAM-IAS U 500-06 standard establishes the requirements to be met by welded steel mesh. The aim of this work is to study the influence of process parameters on the microstructural evolution and mechanical properties of the joints of welded mesh. ATR 500 M ribbed wires of 4 mm in diameter were welded by PW with different welding parameters. The influence of the welding current, welding time, pressure and prewelded time were evaluated. On welded joints, it was characterized the macro and microstructure, microhardness profiles and pull tests were performed. Comparisons with commercial mesh were made and compliance with the requirements of that standard is verified. A strong effect of time and welding current is observed and optimized procedure was obtained.
DOI: 10.6084/m9.figshare.12887312
title: R0189_20170926a_videos

description: Rat 0189, skilled reaching data collected on 9/26/2017 in Leventhal laboratory by Alexandra Bova