cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6273074.v1
title: Recovery Mechanisms in a Compressed Ni-Ti Superelastic Alloy

description: The present work studied the influence of annealing on a Ni-Ti alloy submitted to uniaxial compression. The stress-strain curve under compression showed the absence of the Stress-Induced-Martensite (SIM) plateau and 42% of remaining austenitic phase (B2). identified by the Electron Backscattered Diffraction (EBSD) technique on a Scanning Electronic Microscope (SEM). Annealing at 150 ºC increased the volume fraction of austenite to 70%. Annealing at 200 ºC reduced the volume fraction of austenite to 33% and increased the classical Vickers hardness and the dynamic elastoplastic hardness. This increase suggests the presence of a phase with higher indentation resistance, which can be the R phase reported in the literature. Annealing at 250 ºC decreased the classical Vickers hardness and the dynamic elastoplastic hardness, probably due to recovery. Annealing at 300 ºC advanced the recovery process and promoted some recrystallization, as suggested by the large standard deviation observed in the hardness results.
DOI: 10.6084/m9.figshare.6273071
title: Effect of LZSA Glass-Ceramic Addition on Pressureless Sintered Alumina. Part II: Mechanical Behavior

description: This work aims to evaluate the influence of a Li2O-ZrO2-SiO2-Al2O3 (LZSA) glass-ceramic on the mechanical behavior of alumina. Composites were prepared from alumina with three different particle sizes and 7 to 21 vol% of an LZSA glass-ceramic composition (11.6Li2O-16.8ZrO2-68.2SiO2-3.4Al2O3,). Specimens were obtained by uniaxial pressing. The optimum sintering temperature and holding time were found to be different for each composite. Structural characterization (bulk density and crystalline phases); mechanical characterization (flexure strength, elastic modulus, fracture toughness, and fracture energy); and microstructural analyses were carried out. Fine-grained alumina-based composite containing 21 vol% of glass-ceramic (1470 ºC and 3 h holding time, 2.0% porosity) showed a fracture toughness of 4.93 MPa·m0.5, an elastic modulus of 210 GPa, a fracture energy of 57 J·m-2, and a flexural strength of 170 MPa, in very good agreement with values reported by the literature. An increase of 37-177% in the fracture energy due to 21 vol% LZSA addition in the alumina was achieved for the range of grain size obtained in this work. Even though the final composition included a glassy component, the observed mechanical properties confirmed the effectiveness of the crystalline phases that were formed from LZSA glass-ceramic in reducing the propagation of cracks. The results showed that the addition of the LZSA glass-ceramic improved the mechanical properties of alumina.
DOI: 10.6084/m9.figshare.6273071.v1
title: Effect of LZSA Glass-Ceramic Addition on Pressureless Sintered Alumina. Part II: Mechanical Behavior

description: This work aims to evaluate the influence of a Li2O-ZrO2-SiO2-Al2O3 (LZSA) glass-ceramic on the mechanical behavior of alumina. Composites were prepared from alumina with three different particle sizes and 7 to 21 vol% of an LZSA glass-ceramic composition (11.6Li2O-16.8ZrO2-68.2SiO2-3.4Al2O3,). Specimens were obtained by uniaxial pressing. The optimum sintering temperature and holding time were found to be different for each composite. Structural characterization (bulk density and crystalline phases); mechanical characterization (flexure strength, elastic modulus, fracture toughness, and fracture energy); and microstructural analyses were carried out. Fine-grained alumina-based composite containing 21 vol% of glass-ceramic (1470 ºC and 3 h holding time, 2.0% porosity) showed a fracture toughness of 4.93 MPa·m0.5, an elastic modulus of 210 GPa, a fracture energy of 57 J·m-2, and a flexural strength of 170 MPa, in very good agreement with values reported by the literature. An increase of 37-177% in the fracture energy due to 21 vol% LZSA addition in the alumina was achieved for the range of grain size obtained in this work. Even though the final composition included a glassy component, the observed mechanical properties confirmed the effectiveness of the crystalline phases that were formed from LZSA glass-ceramic in reducing the propagation of cracks. The results showed that the addition of the LZSA glass-ceramic improved the mechanical properties of alumina.
DOI: 10.6084/m9.figshare.6273068
title: Synthesis and Structural Characterization of U-Zr-Nb Alloys

description: U-xZr-yNb alloys with values of x varying from 32% to 50% (wt.%Zr) and y varying from 6% to 10% (wt.%Nb) were produced by the arc melting technique. The effect of the addiction of zirconium and niobium on the phase stabilization of γ-U, lattice parameter, microstructure and elemental composition were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscope (EDS) techniques. The alloys crystallized in a cubic symmetry composed by a γ-U(Zr,Nb) matrix and β-Zr small precipitates, when the content of zirconium and niobium is up to 55 wt.%. With further additions, e.g. 60 wt.%, was observed a highly enriched macrosegregation of β-Zr. It was also observed that the cell size of the γ-U(Zr,Nb) phase increase with the addition of Zr and Nb. The lattice parameter curve behavior as a function of zirconium and niobium deviates from a linear behavior at around x ≈ 50 and y ≈ 10 wt.%.
DOI: 10.6084/m9.figshare.6273068.v1
title: Synthesis and Structural Characterization of U-Zr-Nb Alloys

description: U-xZr-yNb alloys with values of x varying from 32% to 50% (wt.%Zr) and y varying from 6% to 10% (wt.%Nb) were produced by the arc melting technique. The effect of the addiction of zirconium and niobium on the phase stabilization of γ-U, lattice parameter, microstructure and elemental composition were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscope (EDS) techniques. The alloys crystallized in a cubic symmetry composed by a γ-U(Zr,Nb) matrix and β-Zr small precipitates, when the content of zirconium and niobium is up to 55 wt.%. With further additions, e.g. 60 wt.%, was observed a highly enriched macrosegregation of β-Zr. It was also observed that the cell size of the γ-U(Zr,Nb) phase increase with the addition of Zr and Nb. The lattice parameter curve behavior as a function of zirconium and niobium deviates from a linear behavior at around x ≈ 50 and y ≈ 10 wt.%.
DOI: 10.6084/m9.figshare.6273065
title: Selectivity of pesticides registered for soybean crop on Telenomus podisi and Trissolcus basalis

description: ABSTRACT The use of pesticides in the soybean crop may impair the biological control, if the products are not selective to Telenomus podisi and Trissolcus basalis, which are important stink bug egg parasitoids. This study aimed to assess the selectivity of 15 pesticides registered for soybean crop on adults of T. podisi and T. basalis. Three laboratory bioassays were performed, totaling 18 treatments, in a completely randomized design, with four replications. The insecticides (g or mL of a.i.) imidacloprid + beta-cyfluthrin (0.25 + 0.03), deltamethrin (0.06), thiamethoxam + lambda-cyhalothrin (0.27 + 0.35), acephate (1.87) and fenitrothion (1.25) are harmful to both parasitoids species. Flubendiamide (1.20), diflubenzuron (2.00), Bacillus thuringiensis (0.08) and lufenuron (0.12) are innocuous to both parasitoids. The fungicides azoxystrobin + flutriafol (0.31 + 0.31), trifloxystrobin + prothioconazole (0.37 + 0.44), pyraclostrobin + metconazole (0.33 + 0.12) and trifloxystrobin + cyproconazole (0.94 + 0.40) are innocuous to T. podisi, but slightly harmful to T. basalis. The herbicides glufosinate ammonium salt (0.50) and glyphosate isopropylamine salt (1.20) are innocuous to both parasitoids.
DOI: 10.6084/m9.figshare.6273065.v1
title: Selectivity of pesticides registered for soybean crop on Telenomus podisi and Trissolcus basalis

description: ABSTRACT The use of pesticides in the soybean crop may impair the biological control, if the products are not selective to Telenomus podisi and Trissolcus basalis, which are important stink bug egg parasitoids. This study aimed to assess the selectivity of 15 pesticides registered for soybean crop on adults of T. podisi and T. basalis. Three laboratory bioassays were performed, totaling 18 treatments, in a completely randomized design, with four replications. The insecticides (g or mL of a.i.) imidacloprid + beta-cyfluthrin (0.25 + 0.03), deltamethrin (0.06), thiamethoxam + lambda-cyhalothrin (0.27 + 0.35), acephate (1.87) and fenitrothion (1.25) are harmful to both parasitoids species. Flubendiamide (1.20), diflubenzuron (2.00), Bacillus thuringiensis (0.08) and lufenuron (0.12) are innocuous to both parasitoids. The fungicides azoxystrobin + flutriafol (0.31 + 0.31), trifloxystrobin + prothioconazole (0.37 + 0.44), pyraclostrobin + metconazole (0.33 + 0.12) and trifloxystrobin + cyproconazole (0.94 + 0.40) are innocuous to T. podisi, but slightly harmful to T. basalis. The herbicides glufosinate ammonium salt (0.50) and glyphosate isopropylamine salt (1.20) are innocuous to both parasitoids.
DOI: 10.6084/m9.figshare.6273062
title: Microstructure and Properties of Cu-ZrO2 Nanocomposites Synthesized by in Situ Processing

description: In situ chemical reaction method was used to synthesize Cu-ZrO2 nanocomposite powders. The process was carried out by addition of NH4(OH) to certain amount of dispersed Cu(NO3)2·3H2O and ZrOCl2·8H2O solution. Afterwards, a thermal treatment at 650 °C for 1 h was conducted to get the powders of CuO and ZrO2 and remove the remaining liquid. The CuO was then reduced in preferential hydrogen atmosphere into copper. The powders were cold pressed at a pressure of 600 MPa and sintered in a hydrogen atmosphere at 950 °C for 2 h. The structure and characteristics were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results showed that the nanosized ZrO2 particles (with a diameter of about 30-50 nm) was successfully formed and dispersed within the copper matrix. The density, electrical conductivity, mechanical strength measurements (compression strength and Vickers microhardness) and wear properties of Cu-ZrO2 nanocomposite were investigated. Increment in the weight % of ZrO2 nano-particles up to 10 wt.% in the samples, caused the reduction in the densification (7.2%) and electrical conductivity (53.8%) of the nanocomposites. The highest microhardness (146.5 HV) and compressive strength (474.5 MPa) of the nanocomposites is related to the Cu-10 wt.% ZrO2. Owing to the good interfacial bonding between uniformly dispersed ZrO2 nanoparticles and the copper matrix. The abrasive wear rate of the Cu-ZrO2 nanocomposite increased with the increasing load or sliding velocity and is always lower than that of copper at any load or any velocity.
DOI: 10.6084/m9.figshare.6273062.v1
title: Microstructure and Properties of Cu-ZrO2 Nanocomposites Synthesized by in Situ Processing

description: In situ chemical reaction method was used to synthesize Cu-ZrO2 nanocomposite powders. The process was carried out by addition of NH4(OH) to certain amount of dispersed Cu(NO3)2·3H2O and ZrOCl2·8H2O solution. Afterwards, a thermal treatment at 650 °C for 1 h was conducted to get the powders of CuO and ZrO2 and remove the remaining liquid. The CuO was then reduced in preferential hydrogen atmosphere into copper. The powders were cold pressed at a pressure of 600 MPa and sintered in a hydrogen atmosphere at 950 °C for 2 h. The structure and characteristics were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results showed that the nanosized ZrO2 particles (with a diameter of about 30-50 nm) was successfully formed and dispersed within the copper matrix. The density, electrical conductivity, mechanical strength measurements (compression strength and Vickers microhardness) and wear properties of Cu-ZrO2 nanocomposite were investigated. Increment in the weight % of ZrO2 nano-particles up to 10 wt.% in the samples, caused the reduction in the densification (7.2%) and electrical conductivity (53.8%) of the nanocomposites. The highest microhardness (146.5 HV) and compressive strength (474.5 MPa) of the nanocomposites is related to the Cu-10 wt.% ZrO2. Owing to the good interfacial bonding between uniformly dispersed ZrO2 nanoparticles and the copper matrix. The abrasive wear rate of the Cu-ZrO2 nanocomposite increased with the increasing load or sliding velocity and is always lower than that of copper at any load or any velocity.
DOI: 10.6084/m9.figshare.6273059
title: Allelopathy of aqueous Pachyrhizus erosus L. extracts on Euphorbia heterophylla and Bidens pilosa

description: ABSTRACT Allelopathy contributes to the sustainable management of weeds in growing areas, due to its ability to inhibit the development of weed species. This study aimed to evaluate the allelopathic effect of Pachyrhizus erosus extract on Euphorbia heterophylla and Bidens pilosa germination. The experiment was carried out in a completely randomized design, in a 2 x 2 x 4 factorial scheme, with four replications. The first factor corresponded to the plant portion (shoot and tuberous root), the second to the extract preparation method (water at room temperature and boiling) and the third to the extract concentrations (0 %, 25 %, 50 % and 100 %). Phytochemical analyses were performed to identify the presence of secondary metabolites. The variables germination percentage, germination rate index and dry biomass decreased with increasing aqueous extract concentrations for both E. heterophylla and B. pilosa. When applied a P. erosus crude shoot extract (boiling), decreases of 18 % and 92 % were observed in the E. heterophylla and B. pilosa germination, respectively, with a decrease of 91 % in the dry biomass of E. heterophylla seedlings. The tuberous root extract (boiling), on the other hand, reduced the germination percentages for E. heterophylla and B. pilosa in 18 % and 80 %, respectively. The phytochemical evaluation indicated the presence of flavonoids, coumarins and saponins in the shoot and tuberous root extracts, while tannins were only observed in the shoot extract. Thus, it can be concluded that P. erosus extracts display an allelopathic effect on the weed species evaluated.
DOI: 10.6084/m9.figshare.6273059.v1
title: Allelopathy of aqueous Pachyrhizus erosus L. extracts on Euphorbia heterophylla and Bidens pilosa

description: ABSTRACT Allelopathy contributes to the sustainable management of weeds in growing areas, due to its ability to inhibit the development of weed species. This study aimed to evaluate the allelopathic effect of Pachyrhizus erosus extract on Euphorbia heterophylla and Bidens pilosa germination. The experiment was carried out in a completely randomized design, in a 2 x 2 x 4 factorial scheme, with four replications. The first factor corresponded to the plant portion (shoot and tuberous root), the second to the extract preparation method (water at room temperature and boiling) and the third to the extract concentrations (0 %, 25 %, 50 % and 100 %). Phytochemical analyses were performed to identify the presence of secondary metabolites. The variables germination percentage, germination rate index and dry biomass decreased with increasing aqueous extract concentrations for both E. heterophylla and B. pilosa. When applied a P. erosus crude shoot extract (boiling), decreases of 18 % and 92 % were observed in the E. heterophylla and B. pilosa germination, respectively, with a decrease of 91 % in the dry biomass of E. heterophylla seedlings. The tuberous root extract (boiling), on the other hand, reduced the germination percentages for E. heterophylla and B. pilosa in 18 % and 80 %, respectively. The phytochemical evaluation indicated the presence of flavonoids, coumarins and saponins in the shoot and tuberous root extracts, while tannins were only observed in the shoot extract. Thus, it can be concluded that P. erosus extracts display an allelopathic effect on the weed species evaluated.
DOI: 10.6084/m9.figshare.6273056
title: Production of ‘Ubá’ mango tree submitted to rejuvenation pruning and fertilized with nitrogen

description: Abstract The rejuvenation pruning or plant prune is a practice used in fruits species such mango tree, whose plants can exceed ten meters heigh, compromising the implementation of practices such as spraying and harvesting. This study aimed to evaluate the resumption of production of adult ‘Ubá’ mango trees, previously pruned and subjected to fertilization with increasing levels of nitrogen over five seasons. The experiment was conducted in Visconde do Rio Branco, MG. Nineteen years old mango trees were pruned and reduced to the primary branches, about 1.5 m above the ground. Excess shoots were removed, remaining five to six branches per tree. In the year in which the plants were pruned, the nitrogen fertilization was initiated with different doses, divided into three equal fractions, between October of one year and February of the following year. Annually were applied per plant, 160 g of P2O5 in the form of simple superphosphate, 350 g of K2O in the form of potassium chloride, according to the results of the soil analysis, and 0, 175, 350, 525 and 700 g of N in the form of urea. Two years after pruning the plants returned to production, and in the first five crops, we quantified the production in kg per plant and the number of fruits per plant. The production of the mango trees was already stable in the fifth crop or seven years after pruning. The dose of nitrogen resulting in the maximum yield was 238.9 g/plant.
DOI: 10.6084/m9.figshare.6273056.v1
title: Production of ‘Ubá’ mango tree submitted to rejuvenation pruning and fertilized with nitrogen

description: Abstract The rejuvenation pruning or plant prune is a practice used in fruits species such mango tree, whose plants can exceed ten meters heigh, compromising the implementation of practices such as spraying and harvesting. This study aimed to evaluate the resumption of production of adult ‘Ubá’ mango trees, previously pruned and subjected to fertilization with increasing levels of nitrogen over five seasons. The experiment was conducted in Visconde do Rio Branco, MG. Nineteen years old mango trees were pruned and reduced to the primary branches, about 1.5 m above the ground. Excess shoots were removed, remaining five to six branches per tree. In the year in which the plants were pruned, the nitrogen fertilization was initiated with different doses, divided into three equal fractions, between October of one year and February of the following year. Annually were applied per plant, 160 g of P2O5 in the form of simple superphosphate, 350 g of K2O in the form of potassium chloride, according to the results of the soil analysis, and 0, 175, 350, 525 and 700 g of N in the form of urea. Two years after pruning the plants returned to production, and in the first five crops, we quantified the production in kg per plant and the number of fruits per plant. The production of the mango trees was already stable in the fifth crop or seven years after pruning. The dose of nitrogen resulting in the maximum yield was 238.9 g/plant.
DOI: 10.6084/m9.figshare.6273050
title: Mineral composition of leaves and fruits of apple ‘Fuji’ on different rootstocks in the region of São Joaquim-SC

description: Abstract This work evaluated the mineral composition of leaves and fruits of apple (Malus domestica Borkh) ‘Fuji’ on different rootstocks. The experiment was conducted from 2008 to 2011 in the municipality of São Joaquim (SC). The treatments evaluated rootstocks: CG.008, CG.24, CG.56, CG.058, CG.210, CG.213, CG.757, CG.814 and CG.969 of the American series Cornell Geneva (CG); JM.2 and JM.7 of the Japanese series Japan, Morioka (JM); and M.7, M.9 and M.26 of the English series, EMLA (M). The experimental design was randomized blocks with four repetitions. Annually, the leaves were collected for the chemical analysis. Only in the years 2009 and 2010, the fruit samples were collected to determine nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg). The leaf Ca content differed between rootstocks, especially for CG.213 and CG.969, which presented a higher content of the nutrient. However, there were no differences between rootstocks in terms of Ca content in the fruit, which confirms the low ratio between the contents in leaves and fruits. Ratios between nutrients, mainly (K+Mg)/Ca, are more sensitive to the Ca content to discriminate groups of rootstocks about possible risk of physiological disorders in the fruits.
DOI: 10.6084/m9.figshare.6273050.v1
title: Mineral composition of leaves and fruits of apple ‘Fuji’ on different rootstocks in the region of São Joaquim-SC

description: Abstract This work evaluated the mineral composition of leaves and fruits of apple (Malus domestica Borkh) ‘Fuji’ on different rootstocks. The experiment was conducted from 2008 to 2011 in the municipality of São Joaquim (SC). The treatments evaluated rootstocks: CG.008, CG.24, CG.56, CG.058, CG.210, CG.213, CG.757, CG.814 and CG.969 of the American series Cornell Geneva (CG); JM.2 and JM.7 of the Japanese series Japan, Morioka (JM); and M.7, M.9 and M.26 of the English series, EMLA (M). The experimental design was randomized blocks with four repetitions. Annually, the leaves were collected for the chemical analysis. Only in the years 2009 and 2010, the fruit samples were collected to determine nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg). The leaf Ca content differed between rootstocks, especially for CG.213 and CG.969, which presented a higher content of the nutrient. However, there were no differences between rootstocks in terms of Ca content in the fruit, which confirms the low ratio between the contents in leaves and fruits. Ratios between nutrients, mainly (K+Mg)/Ca, are more sensitive to the Ca content to discriminate groups of rootstocks about possible risk of physiological disorders in the fruits.
DOI: 10.6084/m9.figshare.6273047
title: Thermal and Conductivity Studies of VO2+ Doped Methacrylic Acid - Ethyl Acrylate (MAA:EA) Copolymer Films

description: New polymer electrolyte films of Methacrylic Acid - Ethyl Acrylate (MAA:EA) copolymer embedded with different concentrations of VO2+ ions were prepared by solution casting technique. Thermal properties of these films were investigated employing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Electrical conductivity of the films was measured with impedance analyzer in the frequency range of 1 Hz to 1 MHz and in the temperature range of 30 - 70 ºC. It was observed that the magnitude of conductivity increased with the increase in the salt concentration as well as the temperature.
DOI: 10.6084/m9.figshare.6273047.v1
title: Thermal and Conductivity Studies of VO2+ Doped Methacrylic Acid - Ethyl Acrylate (MAA:EA) Copolymer Films

description: New polymer electrolyte films of Methacrylic Acid - Ethyl Acrylate (MAA:EA) copolymer embedded with different concentrations of VO2+ ions were prepared by solution casting technique. Thermal properties of these films were investigated employing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Electrical conductivity of the films was measured with impedance analyzer in the frequency range of 1 Hz to 1 MHz and in the temperature range of 30 - 70 ºC. It was observed that the magnitude of conductivity increased with the increase in the salt concentration as well as the temperature.