cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.9871142
title: Tensile and fatigue properties, machinability and machined surface roughness of Al-Si-Cu alloys

description: ABSTRACT In this paper, the aim was to determine if ASC91 (9 % Al, 1 % Cu) could be replaced with ASC73 (7 % Al, 3 % Cu) aluminium alloy, with presumably improved machinability due to lower silicon content (9 to 7 %) and retained mechanical properties due to a higher copper content (1 to 3 %). The test samples were excised from cylinder heads produced by the lost-foam casting technique in industrial conditions. The tensile properties (proof strength, ultimate tensile strength, elongation and modulus of elasticity), fatigue performance, microstructure and machinability of two as-cast aluminium alloys were examined. The results of the fatigue tests were statistically analyzed using the stair-case method described in the UNI 3964 standard. Tensile properties of the ASC91 were higher, while fatigue properties were higher in the ASC73 alloy. The resultant force was lower for the ASC73, while roughness was lower for the ASC73 alloy, if the feed per tooth is higher than 0.21 mm/t. Two main factors that influence such behaviour are the amount of eutectic silicon and the α-solid solution adhesion to the cutting tool.
DOI: 10.6084/m9.figshare.9871145.v1
title: Rolling and recrystallization behavior of pure zirconium and zircaloy-4

description: ABSTRACT Rolling and recrystallization of pure zirconium and zircaloy-4 have been studied comparatively in this paper. For the as-received condition, zirconium presented a recrystallized microstructure and the alloy a typical basketweave microstructure. Comparative rolling tests were performed, and reduction limit curves as a function of the rolling temperature were determined. At room temperature, pure Zr shows substantial plasticity and the alloy presents low ductility and many cracks. The ductility of both materials increases significantly with an increase in rolling temperature at the range between 300 and 500ºC. In static recrystallization studies, samples of the two materials with similar recrystallized grain size were cold-rolled with a thickness reduction of 55%. During annealing, pure Zr and the alloy soften by recovery and recrystallization, however the relative contribution of recovery is lesser pronounced in the alloy, for which the recrystallization temperature increases by about 60°C.
DOI: 10.6084/m9.figshare.9871148.v1
title: Influence of cutting tool material on the machinability of ABNT 4340 steel in turning

description: ABSTRACT In the present work the aim was to understand the phenomena associated with the machining of ABNT 4340 steel using carbide and cermet cutting tools, both with chipper geometry for light (LP) and medium machining (MP). In this sense, the influence of the variation of the feed rate, the chip breaker and the cutting tool material on the parameters of process response, shear force, shear strength, chip form and analysis of the outlet and gap surfaces of the inserts during the turning operation. Initially, a complete factorial design 23 was used for analysis of shear strength and roughness. In relation to the shear force analysis, the analysis of variance (ANOVA) indicated that the cutting tool material and the feed significantly affected the cutting force, the lowest values being obtained with the cermet cutting tool and the lowest level of advancement. As for Rq roughness, different levels of tool materials or chip breakers were not sufficient to significantly alter the value of Rq. In relation to the chip, the advance and the type of chipbreaker influenced its shape. As a last analysis, it was not possible to identify wear on the cutting tools, for the established cutting parameters and cut path, however, the EDS analysis pointed to the adhesion of material to the clearance and exit surfaces for both tools evaluated.
DOI: 10.6084/m9.figshare.9871136
title: A study of publication trajectories of the Brazilian Computer Science community

description: Abstract: The average faculty productivity have been described as a rapid rise-short peak-gradual decline pattern. Way et al. (2017) have studied this pattern for faculty careers in Computer Science in North America using a piecewise linear model. In this paper, we use a similar methodology and study trajectories (N = 20655) of the Brazilian Computer Science community. First, we have evaluated how the median publication count of researchers is related to institution prestige and public vs. private administration. Second, we have studied how the annual publication rates have increased and its variation according to prestige ranks of institutions. Third, we have found the average trajectory can indeed be described as the canonical rapid increase and slower decrease in productivity. For individual trajectories of senior researchers we have observed only 4.5% of trajectories are well explained by the conventional narrative of rapid rise and gradual decline model. We also have found polynomial models of degrees 1 to 3 explain almost 63.1% of trajectories. The rest of trajectories are considered unstable and not well explained by neither of approaches.
DOI: 10.6084/m9.figshare.9871136.v1
title: A study of publication trajectories of the Brazilian Computer Science community

description: Abstract: The average faculty productivity have been described as a rapid rise-short peak-gradual decline pattern. Way et al. (2017) have studied this pattern for faculty careers in Computer Science in North America using a piecewise linear model. In this paper, we use a similar methodology and study trajectories (N = 20655) of the Brazilian Computer Science community. First, we have evaluated how the median publication count of researchers is related to institution prestige and public vs. private administration. Second, we have studied how the annual publication rates have increased and its variation according to prestige ranks of institutions. Third, we have found the average trajectory can indeed be described as the canonical rapid increase and slower decrease in productivity. For individual trajectories of senior researchers we have observed only 4.5% of trajectories are well explained by the conventional narrative of rapid rise and gradual decline model. We also have found polynomial models of degrees 1 to 3 explain almost 63.1% of trajectories. The rest of trajectories are considered unstable and not well explained by neither of approaches.
DOI: 10.6084/m9.figshare.9871139.v1
title: Evaluation of the corrosion resistance of the vinyltrimethoxsilane film modified with Ce(III) or Ce(IV) ion as carbon steel pretreatment

description: ABSTRACT Silanes are organo functional compounds used as coupling agents between organic-inorganic interfaces, with good adhesion properties. For this reason, the use of silanes as pre-treatment for carbon steel is becoming more and more applicable , since they are also generators of less toxicity residues to the environmental and human health. In order to improve the barrier protection of the silane film and confer self-healing properties, these films can be modified by addition of cerium ions. Thus, these work aims to evaluate the corrosion resistance of vinythrimethoxysilane (VTMOS) film modified with Ce(III) ions or Ce(IV) ions for carbon steel, using the electrochemical impedance spectroscopy (EIS), scanning vibrating electrode technique (SVET), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that Ce(IV) ions addition improved better corrosion resistance than the films with Ce(III) ions. The higher barrier effect is since the film formed in the presence of Ce(IV) ions is better reticulated.
DOI: 10.6084/m9.figshare.9871142.v1
title: Tensile and fatigue properties, machinability and machined surface roughness of Al-Si-Cu alloys

description: ABSTRACT In this paper, the aim was to determine if ASC91 (9 % Al, 1 % Cu) could be replaced with ASC73 (7 % Al, 3 % Cu) aluminium alloy, with presumably improved machinability due to lower silicon content (9 to 7 %) and retained mechanical properties due to a higher copper content (1 to 3 %). The test samples were excised from cylinder heads produced by the lost-foam casting technique in industrial conditions. The tensile properties (proof strength, ultimate tensile strength, elongation and modulus of elasticity), fatigue performance, microstructure and machinability of two as-cast aluminium alloys were examined. The results of the fatigue tests were statistically analyzed using the stair-case method described in the UNI 3964 standard. Tensile properties of the ASC91 were higher, while fatigue properties were higher in the ASC73 alloy. The resultant force was lower for the ASC73, while roughness was lower for the ASC73 alloy, if the feed per tooth is higher than 0.21 mm/t. Two main factors that influence such behaviour are the amount of eutectic silicon and the α-solid solution adhesion to the cutting tool.
DOI: 10.6084/m9.figshare.9871130
title: Antibodies anti-Toxoplasma gondii and anti-Neospora caninum in backyard pigs from the state of Mato Grosso, Brazil

description: Abstract To estimate the seroprevalence of Toxoplasma gondii and Neospora caninum, using an indirect immunofluorescent assay (IFA), and identify the risk factors associated, serum samples were collected from 1,070 pigs from 320 backyard pig farming in the of Mato Grosso state. The animal-level seroprevalence of T. gondii and N. caninum was 32.48% and 13.49%, respectively, with a herd seroprevalence of 55.63% for T. gondii and 27.81% for N. caninum. Feeding the animals with leftovers increases the probability of the presence of anti-T. gondii antibodies in pigs by 1.09-fold. Unlike to T. gondii, feeding with leftovers was found to be negatively associated with N. caninum seropositivity in farm-level analysis and in the animal-level model, so decreasing the chances of positivity. Yet, age was considered a risk factor for N. caninum seropositivity. Further studies are necessary to evaluate the impact of T. gondii infection on backyard pig farming production, and its importance as a source of toxoplasmosis infection in humans in the Mato Grosso state, as well as, the role of domestic pigs in the epidemiology of neosporosis.
DOI: 10.6084/m9.figshare.9871124
title: Influence of public governance on the efficiency in the allocation of public resources

description: Abstract This study sought to verify the influence of public governance practices on the efficiency in the application of public resources in education and health in Brazilian municipalities, based on the perspective of the new public governance (NPG). A municipal efficiency index (MEI) to measure the efficiency in the allocation of public resources in education and health in Brazilian municipalities in 2010. Then, using the statistical models of Ordinary Least Squares, bootstrapped Tobit regression, and quantile regression, the influence of variables considered principles of public governance: transparency/accountability, participation, integrity/ethics, legal conformity, equity, and effectiveness. In conclusion, the study shows that public governance practices influence the efficiency in the application of public resources in education and health in Brazilian municipalities.
DOI: 10.6084/m9.figshare.9871121
title: Construct validation: coping with HIV/AIDS in Primary Health Care

description: ABSTRACT Objective: To validate the construct and measure the trustworthiness of a questionnaire aimed at assessing HIV/AIDS coping actions developed by health professionals in Primary Health Care. Method: A methodological study carried out with 397 primary health care professionals in two municipalities in the Northeast region of Brazil. The construct validity was developed by the exploratory and confirmatory factor analysis, and the reliability analyzed by the reliability and reproducibility. Results: The validation determined six factors retention that composed the six domains of the questionnaire. Internal consistency was 0.91 and quality of the confirmatory analysis adjustment was 0.998 for Goodness of Fit Index. The domains presented Kappa values between 0.833 and 0.997. Conclusions: The final questionnaire was composed of 18 items and presented feasibility of application, and potential to evaluate actions for HIV/AIDS control in Primary Health Care.
DOI: 10.6084/m9.figshare.9871127
title: Application of statistical method in the study of the influence of hydrogen peroxide and sodium borohydride on silver nanoparticle synthesis (AGNPS)

description: ABSTRACT Nanomaterials has attracted a lot of attention in recent years due to its properties that allow applications in several areas such as chemistry, physics, medicine, pharmaceuticals, and engineering. In the nanomaterial universe, silver nanoparticles (AgNPs) have awakened the interest of several researchers because of their bactericidal potential. Recent studies have correlated the efficacy of antimicrobial activity with the surfacevolume ratio, morphology, polydispersity, particle size and AgNPs stability. This work aimed to understand the influence of sodium borohydride (NaBH4) and hydrogen peroxide (H2O2) on the AgNPs properties. The synthesis of AgNPs was performed by chemical reduction of silver ions with sodium borohydride in the presence of hydrogen peroxide and sodium citrate. To determine the influence caused by H2O2 and NaBH4, different concentrations and volume variations were used and a Fisher’s exact test was applied to determine the significance between variables. The samples were characterized by Dynamic Light Scattering (DLS) and Zeta Potential. Results determined that the Fisher’s exact test along with the obtained results of variables of particle size, stability and polydispersity are statistically the same, that is, the variables do not influence statistically the formation of the particles, as well as the influence caused by H2O2 and NaBH4 variation on the AgNPs properties. In summary, variation of NaBH4 concentration and H2O2 volume causes effects under the diameter, stability and polydispersity of AgNPs which have been studied and described herein.
DOI: 10.6084/m9.figshare.9871124.v1
title: Influence of public governance on the efficiency in the allocation of public resources

description: Abstract This study sought to verify the influence of public governance practices on the efficiency in the application of public resources in education and health in Brazilian municipalities, based on the perspective of the new public governance (NPG). A municipal efficiency index (MEI) to measure the efficiency in the allocation of public resources in education and health in Brazilian municipalities in 2010. Then, using the statistical models of Ordinary Least Squares, bootstrapped Tobit regression, and quantile regression, the influence of variables considered principles of public governance: transparency/accountability, participation, integrity/ethics, legal conformity, equity, and effectiveness. In conclusion, the study shows that public governance practices influence the efficiency in the application of public resources in education and health in Brazilian municipalities.
DOI: 10.6084/m9.figshare.9871127.v1
title: Application of statistical method in the study of the influence of hydrogen peroxide and sodium borohydride on silver nanoparticle synthesis (AGNPS)

description: ABSTRACT Nanomaterials has attracted a lot of attention in recent years due to its properties that allow applications in several areas such as chemistry, physics, medicine, pharmaceuticals, and engineering. In the nanomaterial universe, silver nanoparticles (AgNPs) have awakened the interest of several researchers because of their bactericidal potential. Recent studies have correlated the efficacy of antimicrobial activity with the surfacevolume ratio, morphology, polydispersity, particle size and AgNPs stability. This work aimed to understand the influence of sodium borohydride (NaBH4) and hydrogen peroxide (H2O2) on the AgNPs properties. The synthesis of AgNPs was performed by chemical reduction of silver ions with sodium borohydride in the presence of hydrogen peroxide and sodium citrate. To determine the influence caused by H2O2 and NaBH4, different concentrations and volume variations were used and a Fisher’s exact test was applied to determine the significance between variables. The samples were characterized by Dynamic Light Scattering (DLS) and Zeta Potential. Results determined that the Fisher’s exact test along with the obtained results of variables of particle size, stability and polydispersity are statistically the same, that is, the variables do not influence statistically the formation of the particles, as well as the influence caused by H2O2 and NaBH4 variation on the AgNPs properties. In summary, variation of NaBH4 concentration and H2O2 volume causes effects under the diameter, stability and polydispersity of AgNPs which have been studied and described herein.
DOI: 10.6084/m9.figshare.9871130.v1
title: Antibodies anti-Toxoplasma gondii and anti-Neospora caninum in backyard pigs from the state of Mato Grosso, Brazil

description: Abstract To estimate the seroprevalence of Toxoplasma gondii and Neospora caninum, using an indirect immunofluorescent assay (IFA), and identify the risk factors associated, serum samples were collected from 1,070 pigs from 320 backyard pig farming in the of Mato Grosso state. The animal-level seroprevalence of T. gondii and N. caninum was 32.48% and 13.49%, respectively, with a herd seroprevalence of 55.63% for T. gondii and 27.81% for N. caninum. Feeding the animals with leftovers increases the probability of the presence of anti-T. gondii antibodies in pigs by 1.09-fold. Unlike to T. gondii, feeding with leftovers was found to be negatively associated with N. caninum seropositivity in farm-level analysis and in the animal-level model, so decreasing the chances of positivity. Yet, age was considered a risk factor for N. caninum seropositivity. Further studies are necessary to evaluate the impact of T. gondii infection on backyard pig farming production, and its importance as a source of toxoplasmosis infection in humans in the Mato Grosso state, as well as, the role of domestic pigs in the epidemiology of neosporosis.
DOI: 10.6084/m9.figshare.9871118
title: Utilizing Shift-or-Shrink Method to Optimize Multisegment Structures of Bent Optical Waveguides

description: Abstract The authors utilized a heuristic shift-or-shrink method that is associated with the beam propagation method to design an optimal multisegment bent optical waveguide. By transforming the shape of each segment, the multisegment structure of the bent waveguide can be optimized. In addition to achieving maximal transmission efficiency, only four segments are sufficient to satisfactorily improve the transmission performance. Moreover, the optimal path of each of these multisegment bent waveguides remains similar to each other waveguide's optimal path even though the number of the segments increases.
DOI: 10.6084/m9.figshare.9871121.v1
title: Construct validation: coping with HIV/AIDS in Primary Health Care

description: ABSTRACT Objective: To validate the construct and measure the trustworthiness of a questionnaire aimed at assessing HIV/AIDS coping actions developed by health professionals in Primary Health Care. Method: A methodological study carried out with 397 primary health care professionals in two municipalities in the Northeast region of Brazil. The construct validity was developed by the exploratory and confirmatory factor analysis, and the reliability analyzed by the reliability and reproducibility. Results: The validation determined six factors retention that composed the six domains of the questionnaire. Internal consistency was 0.91 and quality of the confirmatory analysis adjustment was 0.998 for Goodness of Fit Index. The domains presented Kappa values between 0.833 and 0.997. Conclusions: The final questionnaire was composed of 18 items and presented feasibility of application, and potential to evaluate actions for HIV/AIDS control in Primary Health Care.
DOI: 10.6084/m9.figshare.9871106
title: Dithiocarbamate Residues in Fruits and Leaves of Passion Fruit (Passiflora edulis) from Different Brazilian Regions

description: Dithiocarbamates are widely used fungicides, including in passion fruit, whose fruits are mainly used for juice production, the leaves for the preparation of herbal tea and medicines. Also, the use of the peel in the food industry has been proposed. In this study, the spectrophotometric method for determination of dithiocarbamate residues, as CS2, in passion fruit (Passiflora edulis) was validated at a limit of quantification (LOQ) of 0.05 mg kg-1 CS2, and 108 samples (55 fruits and 53 leaves) collected from Brazilian growers were analyzed. About 25% of the fruit peel samples were positive (0.06 to 1.4 mg kg-1) and only one sample had residues in the pulp (0.09 mg kg-1), 43.4% of leaf samples contained residues. Washing of fruit reduced the residues in the peel by up to 100%, and drying the leaves increased residue levels by up to 60%. This is the first study that reports dithiocarbamate residues in passion fruit in Brazil, and the results are important for government authorities when planning monitoring programs, and for food and herbal medicine industries.
DOI: 10.6084/m9.figshare.9871109
title: Window dressing in Brazilian investment funds

description: ABSTRACT This paper investigates the presence of window dressing in the Brazilian investment fund market, focusing on equity funds. Window dressing is a practice that presents a particular portfolio composition to the market, which is different from that held by the fund in the reporting period. Just before the end of the period, fund managers change their positions with the aim of presenting safer, more profitable securities portfolios. We believe that there is a lack of empirical evidence on this topic in Brazil. Previous research focuses on diversification, style analysis, fund portfolio turnover, manager profile, and performance. Therefore, we believe that our paper is pioneering in presenting results on window dressing in Brazil. With the presence of window dressing, the market may signal distorted results to investors and guide their allocations towards funds in which they would not invest in the absence of such practices. Moreover, the adoption of window dressing may increase transaction costs and thus destroy value. Our results present a connection with previous studies by Bremer and Kato (1996), O’Neal (2001), Ng and Wang (2004), Ortiz, Sarto, and Vicente (2012), and Agarwal, Gay, and Ling (2014). This paper provides evidence of window dressing in Brazilian equity funds and proposes an empirical study to verify the presence of the practice between 2010 and 2016, using market model residuals, rank gap, and backward holding return gap analysis techniques. In short, our results are consistent with window dressing practices in funds managed by small companies that were losers against the Bovespa Index and presented a high tracking error in the period.
DOI: 10.6084/m9.figshare.9871112
title: Distribution of Metals in the Waters and Sediments of Rivers in Central Amazon Region, Brazil

description: Seasonal concentrations of total, particulate and dissolved Al, Cu, Cd, Cr, Fe, Pb and Ni were analyzed in surface water and total metals in sediment samples from black and whitewater rivers within the Itacoatiara City, Central Amazon. Metals concentrations in water and sediment samples demonstrated that even though urbanization and agricultural practices are common in this region. Metal concentrations in sediments samples are acceptable regarding the recommended levels for protection of aquatic life. From this work, which is the first trace elements study in the main tributaries from Itacoatiara region, we conclude that metals are present in a particulate form, being easier to be transported to other aquatic bodies. During flooding periods an increase of Al, Fe and total organic compound (TOC) in almost water sampling points was observed.