cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6857390
title: Microstructure evolution during high temperature aging of a 35Ni-25Cr-Nb alloy

description: ABSTRACT The dendritic-type microstructure of the 35Ni-25Cr-Nb alloy, in the as-cast condition, consists of an austenitic matrix and two types of eutectic primary carbides; Nb-rich MC type and Cr-rich M23C6 type both presents in interdendritic edges and grain boundaries. During aging at 800ºC for different times, M23C6 type secondary carbides precipitate in the matrix while MC carbides would transform to a Ni-Nb silicide, known as G phase (Ni16Nb6Si7). The microstructure was characterized by optical microscopy, scanning electron microscopy (SEM) with mapping, electron backscatter diffraction (EBSD) and dilatometry, in order to detect the presence of this undesirable phase and analyze the conditions under which it is presented. Silicon was found on edges of primary Nb-rich carbides. This could be indicating that the transformation of this carbide towards silicide rich in Ni and Nb, is in an incipient stage. Apparently, the transformation could be taking place from the outside to the inside of the Nb carbide. In addition, the contraction observed in the dilatometry curve would be associated to the difference on the thermal expansion coefficients between the matrix and the primary eutectic carbides and not to the transformation of the M7C3-type carbide to the M23C6-type.
DOI: 10.6084/m9.figshare.6857390.v1
title: Microstructure evolution during high temperature aging of a 35Ni-25Cr-Nb alloy

description: ABSTRACT The dendritic-type microstructure of the 35Ni-25Cr-Nb alloy, in the as-cast condition, consists of an austenitic matrix and two types of eutectic primary carbides; Nb-rich MC type and Cr-rich M23C6 type both presents in interdendritic edges and grain boundaries. During aging at 800ºC for different times, M23C6 type secondary carbides precipitate in the matrix while MC carbides would transform to a Ni-Nb silicide, known as G phase (Ni16Nb6Si7). The microstructure was characterized by optical microscopy, scanning electron microscopy (SEM) with mapping, electron backscatter diffraction (EBSD) and dilatometry, in order to detect the presence of this undesirable phase and analyze the conditions under which it is presented. Silicon was found on edges of primary Nb-rich carbides. This could be indicating that the transformation of this carbide towards silicide rich in Ni and Nb, is in an incipient stage. Apparently, the transformation could be taking place from the outside to the inside of the Nb carbide. In addition, the contraction observed in the dilatometry curve would be associated to the difference on the thermal expansion coefficients between the matrix and the primary eutectic carbides and not to the transformation of the M7C3-type carbide to the M23C6-type.
DOI: 10.6084/m9.figshare.6857384
title: Accelerated atmospheric corrosion in a cast ASTM A48 gray iron

description: ABSTRACT Due to the long times required to investigate atmospheric corrosion resistance of metals, data on the subject is scarce. One of these studies is the one made by Southwell et al., where the effect of corrosion in a cast gray iron during 16 years was studied in various environments. This research shows and discusses the behavior of cast gray iron when subject to an accelerated corrosion test, which involves wetting in a salt spray chamber, washing and drying cycles during 40 days. Furthermore, samples were submerged in sea water, both natural and UV-sterilized. A direct relationship amongst the presence of bacteria and an increase of surface roughness was found when subject to these conditions during 14 days. Results show that the cast gray iron shows a bimodal behavior, like the observations reported by Melchers on low-alloy steels and the research by Southwell.et al. As described by Melchers, this behavior generates an inflection point in the evolution of corrosion influenced by the presence of bacteria on the metal/corrosion-products interphase. This is validated observing evidence of bacterial activity identifying the presence of sulphur on the corrosion products by EDS after the accelerated corrosion tests. As observed, accelerated corrosion testing can simulate in a short period the conditions under which marine atmospheric corrosion takes place on cast gray iron during years, including the evidence of bacterial activity.
DOI: 10.6084/m9.figshare.6857384.v1
title: Accelerated atmospheric corrosion in a cast ASTM A48 gray iron

description: ABSTRACT Due to the long times required to investigate atmospheric corrosion resistance of metals, data on the subject is scarce. One of these studies is the one made by Southwell et al., where the effect of corrosion in a cast gray iron during 16 years was studied in various environments. This research shows and discusses the behavior of cast gray iron when subject to an accelerated corrosion test, which involves wetting in a salt spray chamber, washing and drying cycles during 40 days. Furthermore, samples were submerged in sea water, both natural and UV-sterilized. A direct relationship amongst the presence of bacteria and an increase of surface roughness was found when subject to these conditions during 14 days. Results show that the cast gray iron shows a bimodal behavior, like the observations reported by Melchers on low-alloy steels and the research by Southwell.et al. As described by Melchers, this behavior generates an inflection point in the evolution of corrosion influenced by the presence of bacteria on the metal/corrosion-products interphase. This is validated observing evidence of bacterial activity identifying the presence of sulphur on the corrosion products by EDS after the accelerated corrosion tests. As observed, accelerated corrosion testing can simulate in a short period the conditions under which marine atmospheric corrosion takes place on cast gray iron during years, including the evidence of bacterial activity.
DOI: 10.6084/m9.figshare.6857393.v1
title: Squeeze Theorem: alternative didactical discussion articulating usual practices and the Geogebra software

description: Abstract In this article, we aim at determining the personal relationship of 1st-year Mozambican undergraduate prospect teachers in mathematics with the Squeeze Theorem and the didactical effectiveness of Geogebra in its discussion in the classroom. The research question was: how did the students, who participated in the experiment, understand the Squeeze Theorem and how would the Geogebra software capitalize the discussion of this theorem in the classroom? We used the Anthropological Theory of Didactics and the Theory of Instrumentation. It was a qualitative research in the shape of a case study. Strategically, we did a preliminary and a priori analysis of the target content, the experiment itself, a posteriori analysis and internal validation of the results. The experiment allowed us to understand how the blended teaching through the computer and usual practices can assist students in understanding the Squeeze Theorem.
DOI: 10.6084/m9.figshare.6857378
title: Magnetic behavior of AISI 304 steel in uniaxial tensile tests

description: ABSTRACT During the magnetization process of a ferromagnetic material, the magnetic domain walls are forced to move due to the magnetic field influence. The domain walls must overcome the stress produced by the pinning sites (grain boundary, dislocations, inclusions, etc.), producing discrete jumps in the magnetization. These jumps can be detected with a sensor coil located on the surface sample, transforming them in voltage pulses known as Magnetic Barkhausen Noise (MBN). This work is the follow-up of the study on the uniaxial tensile test up to breakage, on AISI 304 steel (non-magnetic) samples. As a consequence of the strain a new ferromagnetic phase appears which produces MBN. From the signals obtained during the measurements, a digital filter was designed and applied in order to eliminate any spurious signal and to identify the MBN. For this purpose a Butterworth digital filter was used with a (2-200) kHz bandwidth. This filter was selected because it presents a practically constant response up to the cutoff frequency, giving a flat response over the entire passband. For each load value, the MBN signals were analyzed separately concerning the stages of increase and decrease of the magnetic field excitation. In order to characterize each stage, various statistical parameters were evaluated as a function of the applied strain. Finally, the time evolution of the signals and their root mean square function (RMS) were calculated for each stage of the magnetization, calculating the cross correlation function.
DOI: 10.6084/m9.figshare.6857381
title: Recommendations for the Use of Testosterone in Male Transgender*

description: Abstract Gender incongruence is defined as a condition in which an individual self-identifies and desires to have physical characteristics and social roles that connote the opposite biological sex. Gender dysphoria is when an individual displays the anxiety and/or depression disorders that result from the incongruity between the gender identity and the biological sex. The gender affirmation process must be performed by a multidisciplinary team. The main goal of the hormone treatment is to start the development of male physical characteristics by means of testosterone administration that may be offered to transgender men who are 18 years old or over. The use of testosterone is usually well tolerated and improves the quality of life. However, there is still lack of evidence regarding the effects and risks of the long-term use of this hormone. Many different pharmacological formulations have been used in the transsexualization process. The most commonly used formulation is the intramuscular testosterone esters in a short-term release injection, followed by testosterone cypionate or testosterone enanthate. In the majority of testosterone therapy protocols, the male physical characteristics can be seen in almost all users after 6 months of therapy, and themaximum virilization effects are usually achieved after 3 to 5 years of regular use of the hormone. To minimize risks, plasmatic testosterone levels should be kept within male physiological ranges (300 to 1,000 ng/dl) during hormonal treatment. It is recommended that transgender men under androgen therapy be monitored every 3 months during the 1st year of treatment and then, every 6 to 12 months.
DOI: 10.6084/m9.figshare.6857381.v1
title: Recommendations for the Use of Testosterone in Male Transgender*

description: Abstract Gender incongruence is defined as a condition in which an individual self-identifies and desires to have physical characteristics and social roles that connote the opposite biological sex. Gender dysphoria is when an individual displays the anxiety and/or depression disorders that result from the incongruity between the gender identity and the biological sex. The gender affirmation process must be performed by a multidisciplinary team. The main goal of the hormone treatment is to start the development of male physical characteristics by means of testosterone administration that may be offered to transgender men who are 18 years old or over. The use of testosterone is usually well tolerated and improves the quality of life. However, there is still lack of evidence regarding the effects and risks of the long-term use of this hormone. Many different pharmacological formulations have been used in the transsexualization process. The most commonly used formulation is the intramuscular testosterone esters in a short-term release injection, followed by testosterone cypionate or testosterone enanthate. In the majority of testosterone therapy protocols, the male physical characteristics can be seen in almost all users after 6 months of therapy, and themaximum virilization effects are usually achieved after 3 to 5 years of regular use of the hormone. To minimize risks, plasmatic testosterone levels should be kept within male physiological ranges (300 to 1,000 ng/dl) during hormonal treatment. It is recommended that transgender men under androgen therapy be monitored every 3 months during the 1st year of treatment and then, every 6 to 12 months.
DOI: 10.6084/m9.figshare.6857378.v1
title: Magnetic behavior of AISI 304 steel in uniaxial tensile tests

description: ABSTRACT During the magnetization process of a ferromagnetic material, the magnetic domain walls are forced to move due to the magnetic field influence. The domain walls must overcome the stress produced by the pinning sites (grain boundary, dislocations, inclusions, etc.), producing discrete jumps in the magnetization. These jumps can be detected with a sensor coil located on the surface sample, transforming them in voltage pulses known as Magnetic Barkhausen Noise (MBN). This work is the follow-up of the study on the uniaxial tensile test up to breakage, on AISI 304 steel (non-magnetic) samples. As a consequence of the strain a new ferromagnetic phase appears which produces MBN. From the signals obtained during the measurements, a digital filter was designed and applied in order to eliminate any spurious signal and to identify the MBN. For this purpose a Butterworth digital filter was used with a (2-200) kHz bandwidth. This filter was selected because it presents a practically constant response up to the cutoff frequency, giving a flat response over the entire passband. For each load value, the MBN signals were analyzed separately concerning the stages of increase and decrease of the magnetic field excitation. In order to characterize each stage, various statistical parameters were evaluated as a function of the applied strain. Finally, the time evolution of the signals and their root mean square function (RMS) were calculated for each stage of the magnetization, calculating the cross correlation function.
DOI: 10.6084/m9.figshare.6857372
title: Obtención y caracterización de recubrimientos de biovidrio sobre la aleación de Mg AZ31

description: ABSTRACT The ideal material for a metal bone prosthesis must undergo a gradual corrosion in vivo, without releasing toxic components, while acting as a support and facilitating the growth of bone tissue, until a replacement is completed by the regenerated bone. . Biodegradable magnesium alloys have been studied because of their excellent mechanical properties and biocompatibility. The obstacle that these materials have is its high corrosion rate. Once initiated the process, the pH around tissues rises, interfering with cell growth on the surface of the magnesium alloy. In order to improve the corrosion resistance, the application of protective coatings as an effective solution to this problem is used. A protective film designed for this purpose must have the following characteristics: (i) provide bioactivity required to facilitate bonding between the bone and the material (ii) be compact enough to retard penetration of physiological medium to the alloy facilitating regeneration bone (iii) to have sufficient cohesive strength and adhesion between the coating and the substrate to avoid the film cracking during implantation. This study was prepared by sol-gel material called 45S5 Bioglass® (46.14% SiO2, 26.91% CaO, 24.35% Na2O, 2.60% P2O5,% m) and was deposited on samples of AZ31 magnesium alloy (3% Al , 1% Zn, 0.2% Mn, Fe &lt;0.005%,% m / m), previously polished and washed in ultrasound. The coatings were obtained by the technique of immersion-emersion (dip-coating). Some of the samples were in a pretreatment with aqueous solutions of hot NaOH, in order to provide greater adherence of the vitreous coating. Then a thermal treatment was conducted in air at different temperatures, 400 °C and 430 ºC. To determine the coatings’ corrosion resistance, the polarization curves in simulated physiological medium (SBF) were determined.
DOI: 10.6084/m9.figshare.6857375
title: Ecological anatomy of Eugenia luschnathiana (O.Berg) Klotzsch ex B.D.Jacks. (Myrtaceae) leaves in the Restinga region, state of Ceara

description: Abstract Eugenia luschnathiana (O.Berg) Klotzsch ex B.D.Jacks. (Myrtaceae) species, commonly known as pitomba-da-baía, occurs in Restinga region in the state of Ceara and has medicinal potential. The present study aimed to characterize the anatomy of E. luschnathiana leaves in the rainy and dry seasons, as well as in the sun and shade in the Restinga region of Ceara, aiming to generate useful information to understand the adaptive value of morphoanatomic responses to the natural conditions of occurrence of the species. Collections were performed at the State Botanical Park of Ceara, and leaves were completely expanded and fixed in FAA70, being replaced by 70% ethanol after 24 h. Samples were submitted to standard plant anatomy methodologies in order to qualitatively and quantitatively analyze the leaf blade and petiole structures. As a result, there were differences among sun and shade leaves, rain and dry. In relation to luminosity, most determinations were higher in sun leaves: trichome density and frequency; trichome scar frequency; stomatal frequency, stomatal index, length, width and area of stomata; thickness of leaf blade, mesophyll, cuticle, epidermis, palisade and spongy parenchyma; length and width of the central vein, area of the central vein vascular bundle, number of secretory cavities in the central vein; length and width of the petiole, area of the petiole vascular bundle; amount and area of secretory cavities in the petiole. In shade leaves, only the number of druses in the central vein and petiole were larger. Regarding seasonality, all determinations were higher in the rainy season, except for the length and width of the central vein; number of druses in the central vein and petiole; length of the petiole, area of the vascular bundle and secretory cavities of the petiole. Therefore, it could be concluded that E. luschnathiana has great acclimative capacity to conditions of intense luminosity and periods of water deficit.
DOI: 10.6084/m9.figshare.6857375.v1
title: Ecological anatomy of Eugenia luschnathiana (O.Berg) Klotzsch ex B.D.Jacks. (Myrtaceae) leaves in the Restinga region, state of Ceara

description: Abstract Eugenia luschnathiana (O.Berg) Klotzsch ex B.D.Jacks. (Myrtaceae) species, commonly known as pitomba-da-baía, occurs in Restinga region in the state of Ceara and has medicinal potential. The present study aimed to characterize the anatomy of E. luschnathiana leaves in the rainy and dry seasons, as well as in the sun and shade in the Restinga region of Ceara, aiming to generate useful information to understand the adaptive value of morphoanatomic responses to the natural conditions of occurrence of the species. Collections were performed at the State Botanical Park of Ceara, and leaves were completely expanded and fixed in FAA70, being replaced by 70% ethanol after 24 h. Samples were submitted to standard plant anatomy methodologies in order to qualitatively and quantitatively analyze the leaf blade and petiole structures. As a result, there were differences among sun and shade leaves, rain and dry. In relation to luminosity, most determinations were higher in sun leaves: trichome density and frequency; trichome scar frequency; stomatal frequency, stomatal index, length, width and area of stomata; thickness of leaf blade, mesophyll, cuticle, epidermis, palisade and spongy parenchyma; length and width of the central vein, area of the central vein vascular bundle, number of secretory cavities in the central vein; length and width of the petiole, area of the petiole vascular bundle; amount and area of secretory cavities in the petiole. In shade leaves, only the number of druses in the central vein and petiole were larger. Regarding seasonality, all determinations were higher in the rainy season, except for the length and width of the central vein; number of druses in the central vein and petiole; length of the petiole, area of the vascular bundle and secretory cavities of the petiole. Therefore, it could be concluded that E. luschnathiana has great acclimative capacity to conditions of intense luminosity and periods of water deficit.
DOI: 10.6084/m9.figshare.6857369
title: Study of composition of gaseous phase by FTIR. MoO3 chlorination in presence of sucrose carbon

description: ABSTRACT Chlorination and carbochlorination studies available in the literature were conducted using gravimetric and thermogravimetric techniques. These studies were focused on the overall reaction through analysis of the condensed reaction products, thermodynamic calculations and mass change generated during the reaction. The composition of the gaseous phase in a carbochlorination process is complex; CO, CO2, and COCl2 gases can be formed as well as metal chlorides and/or oxychlorides. In this study, the carbochlorination reaction of MoO3 was studied by IR spectroscopy. This technique allows online detection of gases generated during the reaction. The results obtained by FTIR and other complementary techniques indicated that MoO3 carbochlorination with sucrose carbon proceeds not only with formation of CO2, also CO and HClO were detected. Results proved the formation of a reaction intermediate between Cl2 and carbon surface.
DOI: 10.6084/m9.figshare.6857372.v1
title: Obtención y caracterización de recubrimientos de biovidrio sobre la aleación de Mg AZ31

description: ABSTRACT The ideal material for a metal bone prosthesis must undergo a gradual corrosion in vivo, without releasing toxic components, while acting as a support and facilitating the growth of bone tissue, until a replacement is completed by the regenerated bone. . Biodegradable magnesium alloys have been studied because of their excellent mechanical properties and biocompatibility. The obstacle that these materials have is its high corrosion rate. Once initiated the process, the pH around tissues rises, interfering with cell growth on the surface of the magnesium alloy. In order to improve the corrosion resistance, the application of protective coatings as an effective solution to this problem is used. A protective film designed for this purpose must have the following characteristics: (i) provide bioactivity required to facilitate bonding between the bone and the material (ii) be compact enough to retard penetration of physiological medium to the alloy facilitating regeneration bone (iii) to have sufficient cohesive strength and adhesion between the coating and the substrate to avoid the film cracking during implantation. This study was prepared by sol-gel material called 45S5 Bioglass® (46.14% SiO2, 26.91% CaO, 24.35% Na2O, 2.60% P2O5,% m) and was deposited on samples of AZ31 magnesium alloy (3% Al , 1% Zn, 0.2% Mn, Fe &lt;0.005%,% m / m), previously polished and washed in ultrasound. The coatings were obtained by the technique of immersion-emersion (dip-coating). Some of the samples were in a pretreatment with aqueous solutions of hot NaOH, in order to provide greater adherence of the vitreous coating. Then a thermal treatment was conducted in air at different temperatures, 400 °C and 430 ºC. To determine the coatings’ corrosion resistance, the polarization curves in simulated physiological medium (SBF) were determined.