cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.5907766
title: Nanoporous Gold Surface: An Efficient Platform for Hydrogen Evolution Reaction at Very Low Overpotential

description: A nanostructured porous gold film (NPGF) was fabricated onto a gold electrode surface by an electrochemical approach involving anodization followed by electrochemical reduction in absence of binary alloys, templates and chemical reducing agents. The electrocatalytic activity of the as-fabricated electrocatalyst was examined towards hydrogen evolution reaction (HER) and very low onset potential (−0.048 V) and overpotential values of −0.070 and −0.083 V at current densities of 10 and 20 mA cm -2, respectively, were obtained in 0.5 mol L -1 sulfuric acid solution, along with exchange current density (jo) of 0.126 mA cm -2. A small Tafel slope of ca. 36 mV decade -1 was achieved, indicating the HER takes place according to a Volmer-Heyrovsky mechanism and that the electrochemical desorption of hydrogen is the rate determining step. The performance of the NPGF electrode was compared with that of bulk gold and platinum electrodes, and a platinum-like behavior was noticed for HER. Finally, the durability of the proposed electrocatalyst was examined using voltammetric and amperometric techniques and an excellent stability was achieved.
DOI: 10.6084/m9.figshare.5907766.v1
title: Nanoporous Gold Surface: An Efficient Platform for Hydrogen Evolution Reaction at Very Low Overpotential

description: A nanostructured porous gold film (NPGF) was fabricated onto a gold electrode surface by an electrochemical approach involving anodization followed by electrochemical reduction in absence of binary alloys, templates and chemical reducing agents. The electrocatalytic activity of the as-fabricated electrocatalyst was examined towards hydrogen evolution reaction (HER) and very low onset potential (−0.048 V) and overpotential values of −0.070 and −0.083 V at current densities of 10 and 20 mA cm -2, respectively, were obtained in 0.5 mol L -1 sulfuric acid solution, along with exchange current density (jo) of 0.126 mA cm -2. A small Tafel slope of ca. 36 mV decade -1 was achieved, indicating the HER takes place according to a Volmer-Heyrovsky mechanism and that the electrochemical desorption of hydrogen is the rate determining step. The performance of the NPGF electrode was compared with that of bulk gold and platinum electrodes, and a platinum-like behavior was noticed for HER. Finally, the durability of the proposed electrocatalyst was examined using voltammetric and amperometric techniques and an excellent stability was achieved.
DOI: 10.6084/m9.figshare.5907763
title: Parasites of ornamental fish commercialized in Macapá, Amapá State (Brazil)

description: Abstract This study investigated the parasites fauna of four freshwater ornamental fish species in aquarium shops of Macapá, Amapá State, in addition to survey the commercialized fish species and sanitary conditions of aquarium shops. Different native and non-native ornamental fish species were found in aquarium shops, mainly Poecilidae. We examined 30 specimens of Xiphophorus maculatus, 30 Danio rerio, 30 Paracheirodon axelrodi, and 30 Corydoras ephippifer for parasites. Of the 120 fish examined, 22.5% were parasitized by one or more species and a total of 438 parasites were collected and identified. Parasites such as: Ichthyophthirius multifiliis, Monogenea, undermined Digenea metacercariae, Acanthostomum sp. metacercariae, Camallanus spp., Bothriocephalus acheilognathi and Echinorhynchus sp. infected the hosts examined. Endoparasites in the larval stage showed the greatest diversity and Camallanus spp. was found in all hosts species examined. Paracheirodon axelrodi (43.3%) was the most parasitized host, while C. ephippifer (6.7%) was the least parasitized. Despite the low ectoparasites level, six species of endoparasites was observed, demonstrating that prophylactic and quarantine procedures were not fully adequate. Therefore, failures in prophylactic procedures on any link in the production industry of ornamental fish may cause parasite transmission to ornamental fish captured in different environments and localities.
DOI: 10.6084/m9.figshare.5907763.v1
title: Parasites of ornamental fish commercialized in Macapá, Amapá State (Brazil)

description: Abstract This study investigated the parasites fauna of four freshwater ornamental fish species in aquarium shops of Macapá, Amapá State, in addition to survey the commercialized fish species and sanitary conditions of aquarium shops. Different native and non-native ornamental fish species were found in aquarium shops, mainly Poecilidae. We examined 30 specimens of Xiphophorus maculatus, 30 Danio rerio, 30 Paracheirodon axelrodi, and 30 Corydoras ephippifer for parasites. Of the 120 fish examined, 22.5% were parasitized by one or more species and a total of 438 parasites were collected and identified. Parasites such as: Ichthyophthirius multifiliis, Monogenea, undermined Digenea metacercariae, Acanthostomum sp. metacercariae, Camallanus spp., Bothriocephalus acheilognathi and Echinorhynchus sp. infected the hosts examined. Endoparasites in the larval stage showed the greatest diversity and Camallanus spp. was found in all hosts species examined. Paracheirodon axelrodi (43.3%) was the most parasitized host, while C. ephippifer (6.7%) was the least parasitized. Despite the low ectoparasites level, six species of endoparasites was observed, demonstrating that prophylactic and quarantine procedures were not fully adequate. Therefore, failures in prophylactic procedures on any link in the production industry of ornamental fish may cause parasite transmission to ornamental fish captured in different environments and localities.
DOI: 10.6084/m9.figshare.5907760
title: Prevalence of Eimeria spp. in calves from dairy farms in northern Paraná state, Brazil

description: Abstract Bovine coccidiosis is a disease of major importance in cattle herds across the world. The disorder mainly affects young calves, and E. bovis and E. zuernii are considered the most pathogenic species of the genus, however, E. alabamensis have been described in grazing calves. In this study, the prevalence of Eimeria spp. was evaluated in calves on dairy farms in the northern region of the state of Paraná, Brazil. Four hundred calves on 44 dairy farms were tested for the presence of coccidian oocysts. The positives were re-examined and the oocysts were morphometrically analyzed for species identification. All the farms were contaminated and 205 animals (51.25%) presented Eimeria spp. oocysts. Among these, 146 animals (71.22%) were co-infected by two or more species of coccidia. Ten species of Eimeria were identified: E. bovis (in 30.25% of the positive samples), E. alabamensis (26.75%), E. zuernii (22.00%), E. ellipsoidalis (18.50%), E. auburnensis (13.75%), E. canadensis (8.00%), E. cylindrica (7.25%), E. subspherica (5.00%), E. bukidnonensis (3.00%) and E. brasiliensis (0.75%). This study demonstrates the high prevalence of Eimeria spp. in the northern region of Paraná, Brazil, and detection for the first time in our region the pathogenic species E. alabamensis.
DOI: 10.6084/m9.figshare.5907760.v1
title: Prevalence of Eimeria spp. in calves from dairy farms in northern Paraná state, Brazil

description: Abstract Bovine coccidiosis is a disease of major importance in cattle herds across the world. The disorder mainly affects young calves, and E. bovis and E. zuernii are considered the most pathogenic species of the genus, however, E. alabamensis have been described in grazing calves. In this study, the prevalence of Eimeria spp. was evaluated in calves on dairy farms in the northern region of the state of Paraná, Brazil. Four hundred calves on 44 dairy farms were tested for the presence of coccidian oocysts. The positives were re-examined and the oocysts were morphometrically analyzed for species identification. All the farms were contaminated and 205 animals (51.25%) presented Eimeria spp. oocysts. Among these, 146 animals (71.22%) were co-infected by two or more species of coccidia. Ten species of Eimeria were identified: E. bovis (in 30.25% of the positive samples), E. alabamensis (26.75%), E. zuernii (22.00%), E. ellipsoidalis (18.50%), E. auburnensis (13.75%), E. canadensis (8.00%), E. cylindrica (7.25%), E. subspherica (5.00%), E. bukidnonensis (3.00%) and E. brasiliensis (0.75%). This study demonstrates the high prevalence of Eimeria spp. in the northern region of Paraná, Brazil, and detection for the first time in our region the pathogenic species E. alabamensis.
DOI: 10.6084/m9.figshare.5907754
title: Geochemical Signature of Amazon Tropical Rainforest Soils

description: ABSTRACT: Evaluating soil geochemical diversity in the Amazon Basin has been a challenge largely because most study sites have been at the edge of the basin and it is difficult to get samples in such a region. Here we show that even among the most weathered soils, physicochemical soil properties express lithology. Our results are based on topsoil samples collected from different locations in minimally disturbed areas in the state of Amazonas, Brazil. Soil properties were measured using methods which are suitable for highly developed soils. The Chemical Index Alteration and Weathering Index of Parker was calculated based on the content of metal(loid)s in soils determined by X-ray fluorescence. Descriptive statistics, Pearson correlation, and Principal Component Analysis (PCA) were performed on data. In general, Amazon rainforest soils are more deeply weathered than soils in other Brazilian biomes and tropical rainforests in Asia and Africa. The high coefficient of variation of metal(loid) contents express pedogenesis and parent material diversity. Correlation analysis indicated that the tri-pentavalent elements are strongly associated with Al and Fe contents in the topsoil. In contrast, mono-divalent elements are correlated with sand and silt fractions. According to PCA, five soil groups with defined geochemical compositions and degrees of weathering could be identified: i) acidic sandy podzolized soils; ii) acidic loamy ferralitic soils with the highest content of tri-pentavalent ions; iii) acidic clayey kaolinitic soils with low metal(loid) contents; iv) acidic loamy kaolinitic soils with low metal(loid) contents; and v) silty neutral 2:1 clay soils. This study is the first effort to analyze the geochemical diversity in Amazon rainforest soils. These data are extremely valuable in determining the geochemical background for these soil types and this region. Geochemical variability can be predicted to some extent by lithology and pedogenesis, which can be applied to define the sampling required in future studies.
DOI: 10.6084/m9.figshare.5907754.v1
title: Geochemical Signature of Amazon Tropical Rainforest Soils

description: ABSTRACT: Evaluating soil geochemical diversity in the Amazon Basin has been a challenge largely because most study sites have been at the edge of the basin and it is difficult to get samples in such a region. Here we show that even among the most weathered soils, physicochemical soil properties express lithology. Our results are based on topsoil samples collected from different locations in minimally disturbed areas in the state of Amazonas, Brazil. Soil properties were measured using methods which are suitable for highly developed soils. The Chemical Index Alteration and Weathering Index of Parker was calculated based on the content of metal(loid)s in soils determined by X-ray fluorescence. Descriptive statistics, Pearson correlation, and Principal Component Analysis (PCA) were performed on data. In general, Amazon rainforest soils are more deeply weathered than soils in other Brazilian biomes and tropical rainforests in Asia and Africa. The high coefficient of variation of metal(loid) contents express pedogenesis and parent material diversity. Correlation analysis indicated that the tri-pentavalent elements are strongly associated with Al and Fe contents in the topsoil. In contrast, mono-divalent elements are correlated with sand and silt fractions. According to PCA, five soil groups with defined geochemical compositions and degrees of weathering could be identified: i) acidic sandy podzolized soils; ii) acidic loamy ferralitic soils with the highest content of tri-pentavalent ions; iii) acidic clayey kaolinitic soils with low metal(loid) contents; iv) acidic loamy kaolinitic soils with low metal(loid) contents; and v) silty neutral 2:1 clay soils. This study is the first effort to analyze the geochemical diversity in Amazon rainforest soils. These data are extremely valuable in determining the geochemical background for these soil types and this region. Geochemical variability can be predicted to some extent by lithology and pedogenesis, which can be applied to define the sampling required in future studies.
DOI: 10.6084/m9.figshare.5907751
title: Política Monetária e Preços dos Imóveis no Brasil: Uma análise a partir de um modelo DSGE

description: This paper evaluates whether the recent behavior of the Brazilian Central Bank suggests that monetary policy has reacted to changes in housing prices. To answer this question, two strategies are implemented. Initially, we estimate central bank reaction functions using simple equations methods by Ordinary Least Squares, Generalized Methods of Moments and Full Information Maximum Likelihood. In a second step, we use Bayesian complete information method to estimate central bank reaction functions within a Dynamic Stochastic General Equilibrium model. The results suggest that housing prices have explicitly entered in the decision making process of monetary policy in Brazil.
DOI: 10.6084/m9.figshare.5907751.v1
title: Política Monetária e Preços dos Imóveis no Brasil: Uma análise a partir de um modelo DSGE

description: This paper evaluates whether the recent behavior of the Brazilian Central Bank suggests that monetary policy has reacted to changes in housing prices. To answer this question, two strategies are implemented. Initially, we estimate central bank reaction functions using simple equations methods by Ordinary Least Squares, Generalized Methods of Moments and Full Information Maximum Likelihood. In a second step, we use Bayesian complete information method to estimate central bank reaction functions within a Dynamic Stochastic General Equilibrium model. The results suggest that housing prices have explicitly entered in the decision making process of monetary policy in Brazil.
DOI: 10.6084/m9.figshare.5907748
title: SEQUENTIAL INJECTION ANALYSIS WITH SQUARE WAVE VOLTAMMETRY DETECTION AT GOLD ELECTRODE FOR DETERMINATION OF As(III) IN WATER SAMPLES

description: A sequential injection method with square wave anodic stripping voltammetry (SI-SWASV) using screen printed and crystalline gold electrode was developed for determination of As(III). The carrier solution used for electrode conditioning and stripping medium was composed of 0.050 mol L-1 HCl, whereas the supporting electrode for samples (deposition medium) was 0.50 mol L-1 HCl. The limits of detection and quantification were 20 and 70 nmol L-1 (1.5 and 5.2 µg L-1), respectively. This limit of quantification is almost two times lower than the maximum concentration of As(III) allowed in waters by World Health Organization (10 µg L-1). The sampling throughput was 20 analyses per hour using a sample volume of 1500 µL, pumped through the flow cell at the flow rate of 15 µL s-1. Screen printed gold electrodes were not suitable for work with 0.50 mol L-1 HCl because the results were strongly dependent on the lot of sensors. Crystalline gold electrodes provided reproducible results and the method was applied for determination of As(III) in river water samples. The accuracy was evaluated by recovery studies and analyses by Graphite Furnace Atomic Absorption Spectrometry, providing recoveries between 95 and 108%.
DOI: 10.6084/m9.figshare.5907748.v1
title: SEQUENTIAL INJECTION ANALYSIS WITH SQUARE WAVE VOLTAMMETRY DETECTION AT GOLD ELECTRODE FOR DETERMINATION OF As(III) IN WATER SAMPLES

description: A sequential injection method with square wave anodic stripping voltammetry (SI-SWASV) using screen printed and crystalline gold electrode was developed for determination of As(III). The carrier solution used for electrode conditioning and stripping medium was composed of 0.050 mol L-1 HCl, whereas the supporting electrode for samples (deposition medium) was 0.50 mol L-1 HCl. The limits of detection and quantification were 20 and 70 nmol L-1 (1.5 and 5.2 µg L-1), respectively. This limit of quantification is almost two times lower than the maximum concentration of As(III) allowed in waters by World Health Organization (10 µg L-1). The sampling throughput was 20 analyses per hour using a sample volume of 1500 µL, pumped through the flow cell at the flow rate of 15 µL s-1. Screen printed gold electrodes were not suitable for work with 0.50 mol L-1 HCl because the results were strongly dependent on the lot of sensors. Crystalline gold electrodes provided reproducible results and the method was applied for determination of As(III) in river water samples. The accuracy was evaluated by recovery studies and analyses by Graphite Furnace Atomic Absorption Spectrometry, providing recoveries between 95 and 108%.
DOI: 10.6084/m9.figshare.5907745
title: Assessing Collaboration and Knowledge Flow on Coatings of Metallic Glasses Obtained From Thermal Spraying Processes Using Bibliometrics and Science Mapping

description: Coatings of amorphous metallic alloys can be obtained using different thermal spraying processes, such as HVOF, plasma spraying, cold spraying and others. Although many studies focused on investigating scientific issues concerning apply amorphous metallic coatings using thermal spraying, less attention have been paid to evaluate how research institutes and companies are collaborating and influencing each other to promote new technologies. In this paper, we assessed the collaboration of organizations and the knowledge flow on this relatively new field using bibliometrics and science mapping. The method relies on scientific publications indexed in Web of Science and clustered into research areas using the CWTS Publication-level Classification System. These results provide useful insights about how players are organized and may be used in the context of R&D management, science policy and decision making.
DOI: 10.6084/m9.figshare.5907745.v1
title: Assessing Collaboration and Knowledge Flow on Coatings of Metallic Glasses Obtained From Thermal Spraying Processes Using Bibliometrics and Science Mapping

description: Coatings of amorphous metallic alloys can be obtained using different thermal spraying processes, such as HVOF, plasma spraying, cold spraying and others. Although many studies focused on investigating scientific issues concerning apply amorphous metallic coatings using thermal spraying, less attention have been paid to evaluate how research institutes and companies are collaborating and influencing each other to promote new technologies. In this paper, we assessed the collaboration of organizations and the knowledge flow on this relatively new field using bibliometrics and science mapping. The method relies on scientific publications indexed in Web of Science and clustered into research areas using the CWTS Publication-level Classification System. These results provide useful insights about how players are organized and may be used in the context of R&D management, science policy and decision making.
DOI: 10.6084/m9.figshare.5907742
title: ZEOLITE 4A FOR CLEANSING OF LANDFILL GAS

description: The anaerobic decomposition in landfills produces a gas mixture known as landfill biogas. This biogas consists mainly of CH4 and CO2. The CO2 removal can be carried out by means of adsorption. In order to promote CO2 removal, zeolite type 4A was used as solid adsorbent. The synthesized zeolite was characterized by scanning electron microscopy and X-ray diffraction. CH4/CO2 mixture isotherms were obtained in a magnetic suspension balance equipped with a gas dosing unit and Extended Langmuir and Extended Sips models were used to predict mixture isotherms from monocomponent data. Three biogas emissions drains in a sanitary landfill in Caucaia (Ceará State, Brazil) - ASMOC - were chosen to test the performance of zeolite as CO2 adsorbent under real conditions. Zeolite 4A has proven to be very selective for CO2 even in the presence of H2S.
DOI: 10.6084/m9.figshare.5907742.v1
title: ZEOLITE 4A FOR CLEANSING OF LANDFILL GAS

description: The anaerobic decomposition in landfills produces a gas mixture known as landfill biogas. This biogas consists mainly of CH4 and CO2. The CO2 removal can be carried out by means of adsorption. In order to promote CO2 removal, zeolite type 4A was used as solid adsorbent. The synthesized zeolite was characterized by scanning electron microscopy and X-ray diffraction. CH4/CO2 mixture isotherms were obtained in a magnetic suspension balance equipped with a gas dosing unit and Extended Langmuir and Extended Sips models were used to predict mixture isotherms from monocomponent data. Three biogas emissions drains in a sanitary landfill in Caucaia (Ceará State, Brazil) - ASMOC - were chosen to test the performance of zeolite as CO2 adsorbent under real conditions. Zeolite 4A has proven to be very selective for CO2 even in the presence of H2S.
DOI: 10.6084/m9.figshare.5907739
title: Thermal Spraying Processes and Amorphous Alloys: Macro-Indicators of Patent Activity

description: Thermal spraying processes allows high cooling rates and can favor the formation of amorphous microstructures. Amorphous metallic coatings can result in superior mechanical and functional properties. To follow new technological development and innovation paths, indicators based on patent data can be assembled to support technological forecasting assessments and decision making. This study mapped the technological development on amorphous alloys processed by thermal spraying using patent indicators from documents indexed in the Derwent Innovations Index database between the years 1997 and 2014. We evaluate the patent activity, the role of countries, the main technological subdomains and markets of interest, as well as the main metallic alloys explored as coating. We conclude that new technological developments should be expected in near future and these advances both in amorphous alloys and thermal spraying shall be constantly monitored in the coming years.
DOI: 10.6084/m9.figshare.5907733
title: DFT STUDY ON THE MECHANISTIC, ENERGETIC AND STRUCTURAL ASPECTS OF ADSORPTION OF TIRAPAZAMINE ONTO PRISTINE AND FUNCTIONALIZED CARBON NANOTUBES

description: Using density functional theory, noncovalent interactions and two mechanisms of covalent functionalization of drug tirapazamine with pristine, COOH and COCl functionalized carbon nanotube (NT, NTCOOH and NTCOCl) have been investigated. Quantum molecular descriptors of noncovalent configurations were studied. It was specified that binding of drug tirapazamine with NTCOOH has more binding energy than NTCOCl and NT, so NTCOOH can act as a favorable system for tirapazamine drug delivery within biological and chemical systems (noncovalent). NTCOOH and NTCOCl can bond to the amino group of tirapazamine through OH (COOH mechanism) and Cl (COCl mechanism) groups, respectively. The activation parameters of two pathways were calculated and compared with each other. The activation parameters related to COOH mechanism are higher than those related to COCl mechanism and therefore COCl mechanism is suitable for covalent functionalization. These results could be generalized to other similar drugs.