cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.5907874.v1
title: Severe Plastic Deformation and Additive Distribution in Mg-Fe to Improve Hydrogen Storage Properties

description: Magnesium (Mg) is a light metal with relatively low cost. Its hydride (MgH2) is interesting for the safe hydrogen storage in solid state and has a high gravimetric capacity of 7.6%. Practical application of Mg is still hampered by high reaction temperatures and slow kinetics. In order to improve it and focus on more viable industrial processing conditions, Mg plates, with or without iron (Fe) addition, in the form of wires and powders, were submitted to severe plastic deformation (SPD) in air, starting with extensive cold rolling (ECR), followed by repetitive rolling (ARB). The samples were characterized by X-ray diffraction (XRD), optical microscopy (OM), scanning (SEM) and transmission electron microscopy (TEM). H2 storage properties were evaluated by differential scanning calorimetry (DSC) and Sievert's volumetric method. Mg processed by ECR+ARB resulted in larger grain refinement and densities of cracks than ECR. In addition, Fe in the form of continuous wires was fragmented and resulted in a better distribution of particles than powders, which agglomerated. Thus, finally, the synergetic effect of microstructural features and Fe as catalyst and its distribution improved activation, kinetics and hydrogen storage capacity.
DOI: 10.6084/m9.figshare.5907871.v1
title: Synthesis, Antioxidant Activity, Acetylcholinesterase Inhibition and Quantum Studies of Thiosemicarbazones

description: Thiosemicarbazones are a class of compounds of interest for Medicinal Chemistry, as they are structurally diverse and have numerous biological activities reported in the literature. This study describes the synthesis of seventeen thiosemicarbazones, which were investigated as potential therapeutic agents for the treatment of Alzheimer's disease through antioxidant tests and an inhibitory assay of the acetylcholinesterase enzyme. All compounds showed excellent inhibition of acetylcholinesterase and exhibited excellent antioxidant action when compared to the standards. In addition, a quantum study was carried out, in which the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy values of each compound were obtained. From these theoretical data, chemical properties were calculated and correlated with the experimental data.
DOI: 10.6084/m9.figshare.5907868
title: Coagulation Bath in The Production of Membranes of Nanocomposites Polyamide 6/Clay

description: Membranes of polyamide 6 and its nanocomposites with 3 and 5% of clay were obtained by the phase inversion method using distilled water and solvent as the coagulation bath, 10 and 30% of acid was used, in order to change the membranes morphology/porosity. By XRD analysis, the obtained nanocomposites showed an exfoliated and/or partially exfoliated structure, it was also seen two characteristics peaks of the polyamide 6 phases (α and γ). For the membranes, the characteristic peak γ of the membrane disappeared, being evident the peaks α1 and α2. By SEM the PA6 membrane almost doesn't have pores in its surface, with an addition of clay had an increase in the quantity of surface pores. In the cross section of the PA6 membrane, an extremely thin selective layer, adding the clay the selective layer became thicker and a better defined porous support was obtained. From the acid in the coagulation bath the PA6 membrane continued with a few pores structure. For the nanocomposites there was an increase in size and a better uniformity of the pores. In the cross section the presence of the bath decrease the membrane filtering, also modifying a uniformity of the pores.
DOI: 10.6084/m9.figshare.5907868.v1
title: Coagulation Bath in The Production of Membranes of Nanocomposites Polyamide 6/Clay

description: Membranes of polyamide 6 and its nanocomposites with 3 and 5% of clay were obtained by the phase inversion method using distilled water and solvent as the coagulation bath, 10 and 30% of acid was used, in order to change the membranes morphology/porosity. By XRD analysis, the obtained nanocomposites showed an exfoliated and/or partially exfoliated structure, it was also seen two characteristics peaks of the polyamide 6 phases (α and γ). For the membranes, the characteristic peak γ of the membrane disappeared, being evident the peaks α1 and α2. By SEM the PA6 membrane almost doesn't have pores in its surface, with an addition of clay had an increase in the quantity of surface pores. In the cross section of the PA6 membrane, an extremely thin selective layer, adding the clay the selective layer became thicker and a better defined porous support was obtained. From the acid in the coagulation bath the PA6 membrane continued with a few pores structure. For the nanocomposites there was an increase in size and a better uniformity of the pores. In the cross section the presence of the bath decrease the membrane filtering, also modifying a uniformity of the pores.
DOI: 10.6084/m9.figshare.5907862
title: Evaluation of the Concentration of Cu, Zn, Pb and Cr in Different Fish Species from the São Gonçalo Channel in Pelotas-RS, Brazil

description: The objective of this study was to evaluate the concentration of Cu, Zn, Cr and Pb in different species of fish collected in the estuarine and limnic regions of the São Gonçalo channel, located in the Patos-Mirim lagoon complex in the coastal plain of Rio Grande do Sul State (Southern Brazil) during 2013 (autumn, winter and spring) and 2014 (summer). Fish samples were decomposed in a digester block with a reflux system under conditions optimized using a central composite design as it follows: 250 mg of fish sample, 5 mL HNO3, 2 mL H2O2 during 2 h at 150 °C. The concentrations obtained ranged from 6.7 to 12.0 mg kg -1 for Cu; 1.8 to 23.6 mg kg -1 for Zn; 37 to 487 µg kg -1 for Pb; and 40 to 1268 µg kg -1 for Cr. The highest concentrations of Cu, Zn and Pb, were observed in fishes collected at locations in the estuarine region and Cr showed high levels, especially in the limnic region. The samples of the species Loricariichthys anus (viola) showed the highest concentrations of all analytes investigated.
DOI: 10.6084/m9.figshare.5907862.v1
title: Evaluation of the Concentration of Cu, Zn, Pb and Cr in Different Fish Species from the São Gonçalo Channel in Pelotas-RS, Brazil

description: The objective of this study was to evaluate the concentration of Cu, Zn, Cr and Pb in different species of fish collected in the estuarine and limnic regions of the São Gonçalo channel, located in the Patos-Mirim lagoon complex in the coastal plain of Rio Grande do Sul State (Southern Brazil) during 2013 (autumn, winter and spring) and 2014 (summer). Fish samples were decomposed in a digester block with a reflux system under conditions optimized using a central composite design as it follows: 250 mg of fish sample, 5 mL HNO3, 2 mL H2O2 during 2 h at 150 °C. The concentrations obtained ranged from 6.7 to 12.0 mg kg -1 for Cu; 1.8 to 23.6 mg kg -1 for Zn; 37 to 487 µg kg -1 for Pb; and 40 to 1268 µg kg -1 for Cr. The highest concentrations of Cu, Zn and Pb, were observed in fishes collected at locations in the estuarine region and Cr showed high levels, especially in the limnic region. The samples of the species Loricariichthys anus (viola) showed the highest concentrations of all analytes investigated.
DOI: 10.6084/m9.figshare.5907859
title: Influence of Nanoxides on Diffusivity and Solubility of Hydrogen in Pd-based alloys

description: The hydrogen interaction in palladium alloys with addition of Ce, Zr and Y was studied. These alloys are produced by arc-melting and then cold rolled into thin foils. Heat treatment at 800ºC for 24h in air atmosphere is applied to induce internal oxidation. Hydrogen permeation tests and TDS (Thermal Desorption Spectroscopy) are carried out to evaluate hydrogen interaction with three different microstructures which can be characterized by dislocations, substitutional atoms and nanoxides. For alloys argon annealed, Ce is the element that delays the most hydrogen diffusion, followed by Zr and Y. However alloys with yttrium nanoxides exhibit the highest solubility and the smallest diffusivity due to their small size, spherical shape and dispersion throughout the matrix. Analyzing TDS curves, it is shown that nanoxides are irreversible traps that improve hydrogen stored on palladium alloys. Dislocations and impurity atom on solid solution have little binding energy that detraps hydrogen at smaller temperatures.
DOI: 10.6084/m9.figshare.5907859.v1
title: Influence of Nanoxides on Diffusivity and Solubility of Hydrogen in Pd-based alloys

description: The hydrogen interaction in palladium alloys with addition of Ce, Zr and Y was studied. These alloys are produced by arc-melting and then cold rolled into thin foils. Heat treatment at 800ºC for 24h in air atmosphere is applied to induce internal oxidation. Hydrogen permeation tests and TDS (Thermal Desorption Spectroscopy) are carried out to evaluate hydrogen interaction with three different microstructures which can be characterized by dislocations, substitutional atoms and nanoxides. For alloys argon annealed, Ce is the element that delays the most hydrogen diffusion, followed by Zr and Y. However alloys with yttrium nanoxides exhibit the highest solubility and the smallest diffusivity due to their small size, spherical shape and dispersion throughout the matrix. Analyzing TDS curves, it is shown that nanoxides are irreversible traps that improve hydrogen stored on palladium alloys. Dislocations and impurity atom on solid solution have little binding energy that detraps hydrogen at smaller temperatures.
DOI: 10.6084/m9.figshare.5907856
title: Investigating the atmosphere with data obtained by radiosondes

description: Abstract In this work we present a proposal to investigate the behavior of atmospheric pressure and air temperature with altitude using data from a radiosonde launched by an Upper-air Meteorological Station. Radiosondes, atmospheric sensors transported by balloons, are launched daily to measure pressure, temperature, humidity and wind data at various levels of the atmosphere. In this activity, the teacher has the opportunity to discuss with students various aspects of the atmospheric behavior at altitude. We present two application examples using data from a radiosonde launched at the Upper-air Meteorological Station of Galeão (Rio de Janeiro). Such data can be collected through software-defined radio (RTL-SDR), easy to acquire and configure, or through free-access meteorological sites.
DOI: 10.6084/m9.figshare.5907856.v1
title: Investigating the atmosphere with data obtained by radiosondes

description: Abstract In this work we present a proposal to investigate the behavior of atmospheric pressure and air temperature with altitude using data from a radiosonde launched by an Upper-air Meteorological Station. Radiosondes, atmospheric sensors transported by balloons, are launched daily to measure pressure, temperature, humidity and wind data at various levels of the atmosphere. In this activity, the teacher has the opportunity to discuss with students various aspects of the atmospheric behavior at altitude. We present two application examples using data from a radiosonde launched at the Upper-air Meteorological Station of Galeão (Rio de Janeiro). Such data can be collected through software-defined radio (RTL-SDR), easy to acquire and configure, or through free-access meteorological sites.
DOI: 10.6084/m9.figshare.5907853
title: An evaluation of false-positive rifampicin resistance on the Xpert MTB/RIF

description: BACKGROUND Mycobacterium tuberculosis (MTB) is one of the most significant causes of mortality and morbidity. Early diagnose is important especially in multiple drug resistant tuberculosis to avoid transmission. Traditional techniques requires at least one to three weeks for diagnosis of tuberculosis. Diagnostic delays with multiple drug resistant tuberculosis are associated with worse clinical outcomes and increased transmission The Xpert MTB/RIF assay is one of the new diagnostic device for the diagnosis of tuberculosis and rapid detection of rifampicin resistance. OBJECTIVE We assessed the performance of Xpert MTB/RIF assay for detecting rifampicin resistance using phenotypic drug susceptibility tests as automated BD MGIT 960. METHODS Total of 2136 specimens were included in the study. Xpert MTB/RIF testing was performed on samples, using version 4 cartridges, according to the manufacturer's recommendations. The MTBC culture and first-line phenotypic DST were performed in automated BD MGIT 960 (Becton & Dickinson, USA) according to the recommendations of the manufacturer. Agar proportion was used in the case of inconsistency for rifampicin resistance. FINDINGS Thirty-four samples (19 respiratory and 15 nonrespiratory samples) were determined as positive for M. tuberculosis complex by Xpert MTB/RIF (Cepheid GeneXpert® System, USA). Xpert MTB/RIF assay detected 4/34 (11.7%) specimens as rifampicin resistant. One of the rifampicin resistant isolates was determined susceptible in MGIT 960 automated system. This isolate was also tested with agar proportion method and found susceptible to rifampicin. MAIN CONCLUSION The Xpert MTB/RIF assay can be used as first-line assay for the detection of M. tuberculosis. However, microbiologists must be aware of the limitations of the assay.
DOI: 10.6084/m9.figshare.5907853.v1
title: An evaluation of false-positive rifampicin resistance on the Xpert MTB/RIF

description: BACKGROUND Mycobacterium tuberculosis (MTB) is one of the most significant causes of mortality and morbidity. Early diagnose is important especially in multiple drug resistant tuberculosis to avoid transmission. Traditional techniques requires at least one to three weeks for diagnosis of tuberculosis. Diagnostic delays with multiple drug resistant tuberculosis are associated with worse clinical outcomes and increased transmission The Xpert MTB/RIF assay is one of the new diagnostic device for the diagnosis of tuberculosis and rapid detection of rifampicin resistance. OBJECTIVE We assessed the performance of Xpert MTB/RIF assay for detecting rifampicin resistance using phenotypic drug susceptibility tests as automated BD MGIT 960. METHODS Total of 2136 specimens were included in the study. Xpert MTB/RIF testing was performed on samples, using version 4 cartridges, according to the manufacturer's recommendations. The MTBC culture and first-line phenotypic DST were performed in automated BD MGIT 960 (Becton & Dickinson, USA) according to the recommendations of the manufacturer. Agar proportion was used in the case of inconsistency for rifampicin resistance. FINDINGS Thirty-four samples (19 respiratory and 15 nonrespiratory samples) were determined as positive for M. tuberculosis complex by Xpert MTB/RIF (Cepheid GeneXpert® System, USA). Xpert MTB/RIF assay detected 4/34 (11.7%) specimens as rifampicin resistant. One of the rifampicin resistant isolates was determined susceptible in MGIT 960 automated system. This isolate was also tested with agar proportion method and found susceptible to rifampicin. MAIN CONCLUSION The Xpert MTB/RIF assay can be used as first-line assay for the detection of M. tuberculosis. However, microbiologists must be aware of the limitations of the assay.
DOI: 10.6084/m9.figshare.5907847
title: The Carbon Nanotubes Effect into Single-lap Joint Failure Modes and Load Capacity: a Macromechanical Analysis

description: This study investigates the influence of the adhesive (epoxy resin) thickness and the dispersions of non-functionalized carbon based nanostructures (carbon nanotubes - CNT) on mechanical properties of single-lap bonded joints. To achieve this goal, three CNT concentrations (0.5%, 1.0% and 2.0% m/m); and three different bondline thicknesses (0.05 mm, 0.15 mm and 0.40 mm) were evaluated. The mechanical properties were measured using the apparent shear tensile test, based on ASTM D5868. The results showed that the addition of 1.0 wt% CNTs improved the interface strength, leading to an increase on delaminated areas in failure region up to 55.36% and also improving the peak force up to 13.85%. Decrease in adhesive thickness from 0.40 mm to 0.05 mm promoted a stress redistribution inside adhesive layer improving the peak force up to 13.91%. CNT seems to promote changes in failure modes, light fiber tear (LFT) failure significantly increases up to 45.96%, indicating that interface strength between adhesive and adherent was improved.
DOI: 10.6084/m9.figshare.5907847.v1
title: The Carbon Nanotubes Effect into Single-lap Joint Failure Modes and Load Capacity: a Macromechanical Analysis

description: This study investigates the influence of the adhesive (epoxy resin) thickness and the dispersions of non-functionalized carbon based nanostructures (carbon nanotubes - CNT) on mechanical properties of single-lap bonded joints. To achieve this goal, three CNT concentrations (0.5%, 1.0% and 2.0% m/m); and three different bondline thicknesses (0.05 mm, 0.15 mm and 0.40 mm) were evaluated. The mechanical properties were measured using the apparent shear tensile test, based on ASTM D5868. The results showed that the addition of 1.0 wt% CNTs improved the interface strength, leading to an increase on delaminated areas in failure region up to 55.36% and also improving the peak force up to 13.85%. Decrease in adhesive thickness from 0.40 mm to 0.05 mm promoted a stress redistribution inside adhesive layer improving the peak force up to 13.91%. CNT seems to promote changes in failure modes, light fiber tear (LFT) failure significantly increases up to 45.96%, indicating that interface strength between adhesive and adherent was improved.
DOI: 10.6084/m9.figshare.5907844
title: The Nature of Science in school by means of a educative material on Gravitation

description: Abstract We present in this work the results of a research that aimed to establish a set of suggestions for a didactic treatment of the Nature of Science, with students of physics in High School. To this goal, we developed a teaching unit composed of texts on the development of Gravitation, with an epistemological view based on the elements of Lakatos epistemology, along with electronic presentations and activities based on the subjects studied. Among our findings, we consider aspects related to the use of texts in class, the presentation of specific terms of epistemology to students, and the difficulties faced by both students and teachers when working with the unit.
DOI: 10.6084/m9.figshare.5907844.v1
title: The Nature of Science in school by means of a educative material on Gravitation

description: Abstract We present in this work the results of a research that aimed to establish a set of suggestions for a didactic treatment of the Nature of Science, with students of physics in High School. To this goal, we developed a teaching unit composed of texts on the development of Gravitation, with an epistemological view based on the elements of Lakatos epistemology, along with electronic presentations and activities based on the subjects studied. Among our findings, we consider aspects related to the use of texts in class, the presentation of specific terms of epistemology to students, and the difficulties faced by both students and teachers when working with the unit.
DOI: 10.6084/m9.figshare.5907838
title: DIFFERENT STABILITY METHODS FOR CULTIVAR RECOMMENDATION IN ELEPHANT-GRASS FOR ENERGY PURPOSES IN BRAZIL

description: ABSTRACT The elephant-grass undergoes successive cutting and periodical evaluations that it possible to identify clones with high stability for dry matter production, which can be used for energy production. The present study was carried out to evaluate stability dry matter yield for different parametric and non-parametric methods in elephant grass genotypes for biomass production undergoes successive cutting in the agroclimatic conditions of the Norte Fluminense (RJ, Brazil). The variable measured in the 40 genotypes was dry matter yield (DMY) at 2009, 2010 and 2011 in a field study designed as randomized block design with two replicates. Each sample was grown in different environment condition. The stability methods tested were the Yates and Cochran’s, Plaisted and Peterson’s, Wricke’s ecovalence, Annicchiarico’s, Lin and Binns’ and Kang and Phan’s. Results indicated that cutting (E) and genotypes (G) influenced significantly on the performance of dry matter yield. The non-parametric stability methods were effective for the evaluation of stability in dry matter yield. Genotypes Mercker, Pinda-México, Mercker 86-México, Guaçu/IZ, Mercker Pinda, P-241-Piracicaba and Cubano Pinda were stable stability dry matter yield. Hence, there are genotypes may be exploited in future breeding programmes in order to improve productivity of upland elephant grass over environment.
DOI: 10.6084/m9.figshare.5907838.v1
title: DIFFERENT STABILITY METHODS FOR CULTIVAR RECOMMENDATION IN ELEPHANT-GRASS FOR ENERGY PURPOSES IN BRAZIL

description: ABSTRACT The elephant-grass undergoes successive cutting and periodical evaluations that it possible to identify clones with high stability for dry matter production, which can be used for energy production. The present study was carried out to evaluate stability dry matter yield for different parametric and non-parametric methods in elephant grass genotypes for biomass production undergoes successive cutting in the agroclimatic conditions of the Norte Fluminense (RJ, Brazil). The variable measured in the 40 genotypes was dry matter yield (DMY) at 2009, 2010 and 2011 in a field study designed as randomized block design with two replicates. Each sample was grown in different environment condition. The stability methods tested were the Yates and Cochran’s, Plaisted and Peterson’s, Wricke’s ecovalence, Annicchiarico’s, Lin and Binns’ and Kang and Phan’s. Results indicated that cutting (E) and genotypes (G) influenced significantly on the performance of dry matter yield. The non-parametric stability methods were effective for the evaluation of stability in dry matter yield. Genotypes Mercker, Pinda-México, Mercker 86-México, Guaçu/IZ, Mercker Pinda, P-241-Piracicaba and Cubano Pinda were stable stability dry matter yield. Hence, there are genotypes may be exploited in future breeding programmes in order to improve productivity of upland elephant grass over environment.
DOI: 10.6084/m9.figshare.5907835
title: Teaching Work at Private Language Schools: Direct Speech and the Voice of Hierarchy

description: ABSTRACT This paper aims at focusing on an aspect of the activity of the teacher who works at private language schools. It presents an analysis of teachers’ speeches about their work. These speeches were produced during an interview, which was conceived and applied as a research instrument to generate data. More specifically, our analysis covers the process of their selection and training, which took place before their hiring. The theoretical framework of the investigation are the language sciences from the perspective of the sociological method, as developed by Mikhail Bakhtin and the Circle, and the ergological approach of the activity. In relation to the linguistic-discursive resources used by the teachers during the interviews, it is possible to observe, in the excerpts analyzed in this paper, the constant presence of reported speech, and especially the occurrences of quotations in direct speech, through which an effect of sense of authenticity is produced and the boundaries with respect to the voice of hierarchy are marked. Furthermore, the authoritarian reception of the alien word, the degree of its ideological assurance and also dogmatism explain the use of direct speech.