cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.5980000
title: The Quasi-static and Dynamic Mechanical Behavior of Epoxy Matrix Composites Reinforced with Curaua Fibers

description: The research of natural fiber composites is growing due to the fact that the green materials combine low weight with good mechanical properties. Curaua fiber arises as a competitive natural fiber due to its abundance, low cost and a variety of applications. In this work, different weight fractions of Curaua fiber were used in order to obtain this natural composite material. Specimens of Curaua/Epoxy composites were tested in tensile and in flexion to observe the quasi-static mechanical properties and its physical properties due to temperature variation were evaluated by Dynamic Mechanical Analyses (DMA) analyses. An increase in fiber quantity showed an increase in both the modulus and the strength, leading to a stiff and less ductile material. The results also showed an increase in the viscoelastic stiffness of the epoxy matrix by the incorporation of Curaua fibers. The interaction between Curaua fibers and epoxy matrix affects segmental mobility of the epoxy chains.
DOI: 10.6084/m9.figshare.5980000.v1
title: The Quasi-static and Dynamic Mechanical Behavior of Epoxy Matrix Composites Reinforced with Curaua Fibers

description: The research of natural fiber composites is growing due to the fact that the green materials combine low weight with good mechanical properties. Curaua fiber arises as a competitive natural fiber due to its abundance, low cost and a variety of applications. In this work, different weight fractions of Curaua fiber were used in order to obtain this natural composite material. Specimens of Curaua/Epoxy composites were tested in tensile and in flexion to observe the quasi-static mechanical properties and its physical properties due to temperature variation were evaluated by Dynamic Mechanical Analyses (DMA) analyses. An increase in fiber quantity showed an increase in both the modulus and the strength, leading to a stiff and less ductile material. The results also showed an increase in the viscoelastic stiffness of the epoxy matrix by the incorporation of Curaua fibers. The interaction between Curaua fibers and epoxy matrix affects segmental mobility of the epoxy chains.
DOI: 10.6084/m9.figshare.5979994
title: Tropical soils characterization at low cost and time using portable X-ray fluorescence spectrometer (pXRF): Effects of different sample preparation methods

description: ABSTRACT Portable X-ray fluorescence spectrometer (pXRF) has been recently adopted by the Soil Science community for uses in both field and laboratory, obtaining the total content of several chemical elements in a few seconds. Sulfuric acid digestion is an expensive and time-consuming laboratory analysis that provides contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5, important for soil studies. Due to few pXRF studies in tropical soils, this work aimed to compare contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5 obtained by pXRF with sulfuric acid digestion results, and to evaluate the effects of varying forms of preparing soil samples and scanning with pXRF on the resulting values in Brazilian soils. Soils were scanned in five conditions in-field (in situ) and in laboratory, evaluating varying sample preparation methods, particle sizes and soil moisture. Four pXRF scanning operational modes were tested. Linear regressions were adjusted between results of pXRF and sulfuric acid digestion. Equations were validated with an independent set of samples. Statistical analyses compared the methods of preparing the samples. Adequate linear models reached R2 of 0.99 and 0.89 for Fe2O3 and TiO2, respectively. Validation promoted R2 greater than 0.97 and RMSE and ME close to zero for both oxides. Statistical differences of pXRF results were found among the methods of preparing samples. pXRF spectrometer has great potential to obtain Fe2O3 and TiO2 content rapidly and economically with high correspondence with laboratory results of sulfuric acid digestion analysis. Varying methods of preparing the samples promote differences in the results of pXRF.
DOI: 10.6084/m9.figshare.5979994.v1
title: Tropical soils characterization at low cost and time using portable X-ray fluorescence spectrometer (pXRF): Effects of different sample preparation methods

description: ABSTRACT Portable X-ray fluorescence spectrometer (pXRF) has been recently adopted by the Soil Science community for uses in both field and laboratory, obtaining the total content of several chemical elements in a few seconds. Sulfuric acid digestion is an expensive and time-consuming laboratory analysis that provides contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5, important for soil studies. Due to few pXRF studies in tropical soils, this work aimed to compare contents of Fe2O3, Al2O3, SiO2, TiO2 and P2O5 obtained by pXRF with sulfuric acid digestion results, and to evaluate the effects of varying forms of preparing soil samples and scanning with pXRF on the resulting values in Brazilian soils. Soils were scanned in five conditions in-field (in situ) and in laboratory, evaluating varying sample preparation methods, particle sizes and soil moisture. Four pXRF scanning operational modes were tested. Linear regressions were adjusted between results of pXRF and sulfuric acid digestion. Equations were validated with an independent set of samples. Statistical analyses compared the methods of preparing the samples. Adequate linear models reached R2 of 0.99 and 0.89 for Fe2O3 and TiO2, respectively. Validation promoted R2 greater than 0.97 and RMSE and ME close to zero for both oxides. Statistical differences of pXRF results were found among the methods of preparing samples. pXRF spectrometer has great potential to obtain Fe2O3 and TiO2 content rapidly and economically with high correspondence with laboratory results of sulfuric acid digestion analysis. Varying methods of preparing the samples promote differences in the results of pXRF.
DOI: 10.6084/m9.figshare.5979988
title: Microstructural and Electrochemical behaviour of Aluminium Alloy Composites Produced Using Different Sintering Techniques

description: Present research work analyses the effect of heating modes on the densification, microstructure and mechanical properties of aluminum alloys [65Al-20Cu-15Mn] fabricated through powder metallurgy route. Sintering of compacts using conventional, microwave and spark plasma sintering methods has been carried out at 525°C. From the results, it has been observed that the spark plasma sintering method produced the samples with better mechanical properties than the other two methods, followed by microwave and conventionally sintered counterparts. Microstructural analysis using optical microscopy revealed that spark plasma sintered sample has finest microstructure due to faster rate of heating than microwave and conventional methods.
DOI: 10.6084/m9.figshare.5979988.v1
title: Microstructural and Electrochemical behaviour of Aluminium Alloy Composites Produced Using Different Sintering Techniques

description: Present research work analyses the effect of heating modes on the densification, microstructure and mechanical properties of aluminum alloys [65Al-20Cu-15Mn] fabricated through powder metallurgy route. Sintering of compacts using conventional, microwave and spark plasma sintering methods has been carried out at 525°C. From the results, it has been observed that the spark plasma sintering method produced the samples with better mechanical properties than the other two methods, followed by microwave and conventionally sintered counterparts. Microstructural analysis using optical microscopy revealed that spark plasma sintered sample has finest microstructure due to faster rate of heating than microwave and conventional methods.
DOI: 10.6084/m9.figshare.5979985
title: Negative incentives and sustainability in the amazonian logging industry

description: Abstract: This paper investigates the existence of lock-in of low technology and high environmental impact on Brazilian Amazon logging industry. The research employed evolutionary economics as a theoretical basis, especially the concept of technological trajectories. The duality of decisions involving logging - conventional logging (CL) versus reduced-impact logging (RIL) - was studied. An agent-based simulation model - in which decision-making under bounded rationality is based on a genetic algorithm - was implemented in Java programming language. Results demonstrate the existence of lock-in, producers aversion to risks, greater operational efficiency of sustainable logging, and benefits derived from a policy of environmental bonuses, both in economic and ecological terms.
DOI: 10.6084/m9.figshare.5979985.v1
title: Negative incentives and sustainability in the amazonian logging industry

description: Abstract: This paper investigates the existence of lock-in of low technology and high environmental impact on Brazilian Amazon logging industry. The research employed evolutionary economics as a theoretical basis, especially the concept of technological trajectories. The duality of decisions involving logging - conventional logging (CL) versus reduced-impact logging (RIL) - was studied. An agent-based simulation model - in which decision-making under bounded rationality is based on a genetic algorithm - was implemented in Java programming language. Results demonstrate the existence of lock-in, producers aversion to risks, greater operational efficiency of sustainable logging, and benefits derived from a policy of environmental bonuses, both in economic and ecological terms.
DOI: 10.6084/m9.figshare.5979982
title: Metacognition Assessment Scale for the Elderly: Validity and Internal Consistency

description: ABSTRACT The aim of this study was to investigate the validity and accuracy of an instrument which assess metacognition in the elderly called Metacognitive Senior Scale (EMETA-S). A sample of 194 elderly of both sexes participated. They answered the EMETA-S, consisting of 74 items. Factor analysis with varimax rotation was performed and revealed the presence of two factors accounted for 27.18% of the variance of the scale. After deleting items, the EMETA-S was composed of 27 items with internal consistency of 0.85. No significant differences were found between the average performance according to the variables of sex, age and education of the participants. The analysis of the validity and accuracy indicated adequacy of the items and good internal consistency of the scale.
DOI: 10.6084/m9.figshare.5979979
title: High energy Gallium Arsenide laser does not facilitate collagen alteration in muscle skeletal extracellular matrix: experimental study

description: Abstract Introduction: Low intensity laser therapy has proven effective in treating different tissues, reducing inflammation, preventing the formation of fibrous tissue, and promoting muscle regeneration. Objective: To evaluate the effect of low intensity laser therapy, seven days after the injury, and verify whether the radiated energy chosen influences the formation of fibrous tissue. Methods: Thirty Wistar rats, adult male, average body weight 210-340 g were used. The animals were randomized into three groups: control group, untreated injured group (L), and injured and treated group (LT). After anesthetizing the animals, muscle injury was induced by freezing (cryoinjury) in the central region of the tibialis anterior muscle belly (TA) on the left hind limb, through an iron rod previously immersed in liquid nitrogen. A Gallium Arsenide laser, wavelength 904 nm was used. The applications were initiated 24 hours after injury, daily, for five days, at two points in the lesion area. After 7 days, the animals were euthanized; the TA muscle of the left hind limb was removed and frozen in liquid nitrogen and the obtained histological sections were subjected to Sirius Red staining. Results: Histological analysis showed no significant difference in relation to the area of fibrosis in the LT and L groups. Conclusion: The results suggest that the energy density of 69 J/cm² and final energy (4.8 joules) did not promote alterations in the area of collagen in the skeletal muscle extracellular matrix.
DOI: 10.6084/m9.figshare.5979979.v1
title: High energy Gallium Arsenide laser does not facilitate collagen alteration in muscle skeletal extracellular matrix: experimental study

description: Abstract Introduction: Low intensity laser therapy has proven effective in treating different tissues, reducing inflammation, preventing the formation of fibrous tissue, and promoting muscle regeneration. Objective: To evaluate the effect of low intensity laser therapy, seven days after the injury, and verify whether the radiated energy chosen influences the formation of fibrous tissue. Methods: Thirty Wistar rats, adult male, average body weight 210-340 g were used. The animals were randomized into three groups: control group, untreated injured group (L), and injured and treated group (LT). After anesthetizing the animals, muscle injury was induced by freezing (cryoinjury) in the central region of the tibialis anterior muscle belly (TA) on the left hind limb, through an iron rod previously immersed in liquid nitrogen. A Gallium Arsenide laser, wavelength 904 nm was used. The applications were initiated 24 hours after injury, daily, for five days, at two points in the lesion area. After 7 days, the animals were euthanized; the TA muscle of the left hind limb was removed and frozen in liquid nitrogen and the obtained histological sections were subjected to Sirius Red staining. Results: Histological analysis showed no significant difference in relation to the area of fibrosis in the LT and L groups. Conclusion: The results suggest that the energy density of 69 J/cm² and final energy (4.8 joules) did not promote alterations in the area of collagen in the skeletal muscle extracellular matrix.
DOI: 10.6084/m9.figshare.5979976
title: Burnout syndrome in physicians: a systematic review

description: Abstract Introduction: physicians are highly vulnerable to Burnout Syndrome (BS) because they deal with stressors throughout their professional lives. Objective: to identify the frequency of BS in different medical specialties and its possible associated factors. Methods: systematic review according to the PRISMA statement, using LILACS, MEDLINE, PubMed and SciELO databases, and selecting studies that use the Maslach Burnout Inventory to identify and quantify the syndrome. Results: 22 medical specialties were identified as related to BS. The five specialties with the highest prevalence of BS cases were, in decreasing order: intensive care unit medicine, family medicine, emergency medicine, internal medicine and orthopedics. Discussion: the syndrome etiology is multifactorial. There are factors associated with BS that contribute to the onset of the syndrome and others that may prevent its outcome. Factors that are common to medical practice and others associated with medical specialties were identified. The main factors associated with BS are those related to work organization and environment and the way physicians cope with stress.
DOI: 10.6084/m9.figshare.5979976.v1
title: Burnout syndrome in physicians: a systematic review

description: Abstract Introduction: physicians are highly vulnerable to Burnout Syndrome (BS) because they deal with stressors throughout their professional lives. Objective: to identify the frequency of BS in different medical specialties and its possible associated factors. Methods: systematic review according to the PRISMA statement, using LILACS, MEDLINE, PubMed and SciELO databases, and selecting studies that use the Maslach Burnout Inventory to identify and quantify the syndrome. Results: 22 medical specialties were identified as related to BS. The five specialties with the highest prevalence of BS cases were, in decreasing order: intensive care unit medicine, family medicine, emergency medicine, internal medicine and orthopedics. Discussion: the syndrome etiology is multifactorial. There are factors associated with BS that contribute to the onset of the syndrome and others that may prevent its outcome. Factors that are common to medical practice and others associated with medical specialties were identified. The main factors associated with BS are those related to work organization and environment and the way physicians cope with stress.
DOI: 10.6084/m9.figshare.5979970
title: Efficiency of the Brazilian banking industry during the period of 2006-2013: domestic banks x foreign banks

description: Abstract: After the implementation of the Real Plan in 1994, the Brazilian banking industry has undergone profound structural changes, in which the production efficiency and the presence of foreign banks in the national economy have become more important for the sector. The debate on the presence of foreign banks in domestic economies and its consequences in the banking industry efficiency is subject of much discussion. This paper aims to test if foreign banks in the Brazilian market were more efficient than domestic banks between 2006 and 2013, using Data Envelopment Analysis (DEA). After having calculated the operational efficiency measures and obtained the efficient frontiers, the results pointed to a Brazilian banking industry dominated by domestic banks, and, in the period of 2006-2013, these were more efficient than their foreign competitors, while the overall efficiency of the Brazilian banking industry, on average, has deteriorated.
DOI: 10.6084/m9.figshare.5979970.v1
title: Efficiency of the Brazilian banking industry during the period of 2006-2013: domestic banks x foreign banks

description: Abstract: After the implementation of the Real Plan in 1994, the Brazilian banking industry has undergone profound structural changes, in which the production efficiency and the presence of foreign banks in the national economy have become more important for the sector. The debate on the presence of foreign banks in domestic economies and its consequences in the banking industry efficiency is subject of much discussion. This paper aims to test if foreign banks in the Brazilian market were more efficient than domestic banks between 2006 and 2013, using Data Envelopment Analysis (DEA). After having calculated the operational efficiency measures and obtained the efficient frontiers, the results pointed to a Brazilian banking industry dominated by domestic banks, and, in the period of 2006-2013, these were more efficient than their foreign competitors, while the overall efficiency of the Brazilian banking industry, on average, has deteriorated.
DOI: 10.6084/m9.figshare.5979967
title: Treadmill in Parkinson’s: influence on gait, balance, BDNF and Reduced Glutathione

description: Abstract Introduction: Parkinson’s disease (PD) is characterized by nigrostriatal degeneration, with dopaminergic depletion, and inflammatory and oxidative changes in the brain, leading to movement and coordination disorders. Recent studies have shown that treadmill training can be beneficial for these patients, but there is little evidence assessing the related blood parameters, such as oxidative stress and neurotrophin levels. Objective: Assess the influence of treadmill training for patients with Parkinson’s on gait, balance, Brain-Derived Neurotrophic Factor (BDNF) and reduced glutathione. Methods: Twenty-two patients with PD (Hoehn and Yahr II and III), older than 40 years, were randomly allocated to two groups: CG (n = 12) - drug treatment and IG (n = 10) - treadmill. Assessments related to functional capacity (quality of life, static and dynamic analysis of gait) and blood parameters such as GSH and BDNF were conducted before and after the eight-week intervention. Results: The demographic data of the groups were homogeneous in terms of age, sex, height, weight, time since disease onset, mini mental examination and the geriatric depression scale. Significant intergroup differences were found for the mental component summary, surface variation, latero-lateral oscillation, antero-posterior oscillation and mean velocity in the post-intervention period. The IG exhibited a strong association between BDNF and GSH, with statistically significant values. Conclusion: It was concluded that controlled treadmill walking improves static balance, quality of life and plasma BDNF and GSH levels in patients with PD.
DOI: 10.6084/m9.figshare.5979967.v1
title: Treadmill in Parkinson’s: influence on gait, balance, BDNF and Reduced Glutathione

description: Abstract Introduction: Parkinson’s disease (PD) is characterized by nigrostriatal degeneration, with dopaminergic depletion, and inflammatory and oxidative changes in the brain, leading to movement and coordination disorders. Recent studies have shown that treadmill training can be beneficial for these patients, but there is little evidence assessing the related blood parameters, such as oxidative stress and neurotrophin levels. Objective: Assess the influence of treadmill training for patients with Parkinson’s on gait, balance, Brain-Derived Neurotrophic Factor (BDNF) and reduced glutathione. Methods: Twenty-two patients with PD (Hoehn and Yahr II and III), older than 40 years, were randomly allocated to two groups: CG (n = 12) - drug treatment and IG (n = 10) - treadmill. Assessments related to functional capacity (quality of life, static and dynamic analysis of gait) and blood parameters such as GSH and BDNF were conducted before and after the eight-week intervention. Results: The demographic data of the groups were homogeneous in terms of age, sex, height, weight, time since disease onset, mini mental examination and the geriatric depression scale. Significant intergroup differences were found for the mental component summary, surface variation, latero-lateral oscillation, antero-posterior oscillation and mean velocity in the post-intervention period. The IG exhibited a strong association between BDNF and GSH, with statistically significant values. Conclusion: It was concluded that controlled treadmill walking improves static balance, quality of life and plasma BDNF and GSH levels in patients with PD.
DOI: 10.6084/m9.figshare.5979964
title: Corrosion Behavior of Plasma Nitrided and Nitrocarburised Supermartensitic Stainless Steel

description: Supermartensitic stainles steels (SMSS's) are a new generation of martensitic steels that have been increasingly used in oil and gas applications due to their adequate corrosion resistance and mechanical properties. In the present study, SMSS specimens (UNS S41425) were solution heat treated and air cooled followed by plasma nitriding and nitrocarburising at 400, 450 and 500°C for 5h. The produced layers were characterized by optical microscopy, microhardness testing, X-ray diffraction and corrosion testing in NaCl 3.5% solution. Surface alloying with nitrogen or both nitrogen and carbon results in increased surface hardness and homogeneous layers in which layer thickness increases with temperature. However, plasma nitriding yields a slightly thicker case than nitrocarburising. X-ray diffraction indicates very broad and overlapped peaks for the treatments conducted at 400°C. Increasing treatment temperature appears to result in the formation of chromium nitrides and iron nitrides and carbides, depending on the treatment. It was also found that treatment temperature drastically affects the corrosion response of the steel. The untreated steel presented a pitting potential close to 250mV. Plasma nitriding at 400°C was the only condition in which significant improvement of corrosion is observed. For plasma nitriding and nitrocarburising at 450 and 500°C, some pitting was detected.