cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7244243
title: Eucalypts wood glue with natural adhesives

description: ABSTRACT Tannins of eucalyptus bark were obtained by extracting with water under addition of 8% Na2CO3 and 4% Na2SO4. To determine the adhesive properties was evaluated the viscosity, density, solids, gel time, and pH of adhesive of black wattle 50%, urea 100%, tannin extracted from the eucalyptus bark with Na2CO3 30% and Na2SO4 50%, and urea with tannin extracted from the eucalyptus bark of ratio of 90:10 and 80:20. Waste eucalypts wood (density classified into three classes: low, medium and high) were glued to the hot tannic and synthetic adhesives. The resistance was determined by the glued joints shear strength and wood failure. It can be concluded that the adhesive compounds by tannin extracted with sodium sulphate and pure sodium carbonate (100%) had desirable characteristics for the production of tannins, but not enough for its use as adhesive wood in its entirety and it may be used in the urea-formaldehyde glue gem enrichment in the timber. The higher shear strength on wood occurred in the high density class for all adhesives used, while larger gaps in wood adhesives in most tests it occurred in the wooden low densities.
DOI: 10.7284/135127
title: Meteorological Station data collected during research cruise SKQ201912S using a Vaisala WXT520 instrument system onboard the platform RV Sikuliaq

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7244243.v1
title: Eucalypts wood glue with natural adhesives

description: ABSTRACT Tannins of eucalyptus bark were obtained by extracting with water under addition of 8% Na2CO3 and 4% Na2SO4. To determine the adhesive properties was evaluated the viscosity, density, solids, gel time, and pH of adhesive of black wattle 50%, urea 100%, tannin extracted from the eucalyptus bark with Na2CO3 30% and Na2SO4 50%, and urea with tannin extracted from the eucalyptus bark of ratio of 90:10 and 80:20. Waste eucalypts wood (density classified into three classes: low, medium and high) were glued to the hot tannic and synthetic adhesives. The resistance was determined by the glued joints shear strength and wood failure. It can be concluded that the adhesive compounds by tannin extracted with sodium sulphate and pure sodium carbonate (100%) had desirable characteristics for the production of tannins, but not enough for its use as adhesive wood in its entirety and it may be used in the urea-formaldehyde glue gem enrichment in the timber. The higher shear strength on wood occurred in the high density class for all adhesives used, while larger gaps in wood adhesives in most tests it occurred in the wooden low densities.
DOI: 10.6084/m9.figshare.7244246.v1
title: Numerical Studies of Penetration in Light Armor, Concrete and Brick-Wall Targets

description: ABSTRACT The accurate numerical simulation of projectile penetration process is a complex challenge. Experimental investigation of these time-dependent non-linear events is expensive and time-consuming. In this paper, 3-D numerical simulations are carried out to estimate the penetration performance of designed penetrators against the double and triple brick-wall, plain concrete wall and light armor targets at impact velocities of 120 to 300 m/s, undergoing normal and oblique impacts. In all simulations, both the projectile and targets are modeled using Lagrange solver facility, available in ANSYS/Autodyn. During penetration process, targets experience severe grid deformation in the region local to the penetrator. Highly distorted elements are removed from the calculation using erosion strain algorithm. The simulation results suggest that at maximum velocity flat-nose (FN) projectile successfully perforate all the targets with significant residual velocity, for both normal and maximum oblique impact scenarios. For impact velocity of 120 m/s, the FN projectile perforated the armor and concrete targets but was not able to penetrate and cross through these targets. However, both brick-wall targets were perforated at normal and maximum oblique angle with sufficient residual velocity. The validation of the calculated results and numerical setup were made with experiments against double and triple brick-wall targets for impacting velocity of 170 m/s. Good agreement between the experimental and estimated projectile residual velocity has been achieved. In contrast to FN projectile, the ogive-nose penetrator calculated results has shown ricocheting behavior on impacting the light armor target at minimum velocity and maximum obliquity. The FN projectile has shown better perforation and penetration performance against light armor and domestic targets. The projectile minimum velocity is also estimated numerically to fully penetrate three different types of targets. These results would be beneficial for the designers and operators to get the desired performance against domestic and light armor targets with sureness.
DOI: 10.6084/m9.figshare.7244237
title: Effects of pre-treatment of Curauá fibers on compatibility with portland cements

description: ABSTRACT There has been ever growing interest in the construction industry in using lighter, eco-friendly and sustainable materials, while maintainingthe desirable mechanical properties. The objective of the present work was to evaluate the effects of pre-treatments on chemical compatibility between Curauá fiber (Ananas erectifolius) and Portland cement. In the inhibition test, cement hydration temperature evolution wasmeasured in the absence and presence of untreated and treated Curauá fibers (cold water, hot water and NaOH). The chemical characterization of untreated Curauá fibers was done by determining the content of extractives, lignin, holocellulose and ashes. Thee Segal's method was used for determinate the crystallinity index on untreated and treated fibers. The inhibition test graded the untreated fiber as high inhibition, showing the need to provide it a treatment. Treatments done on Curauá fibers removed some amorphous components of the fibers affected positively the compatibility between cement and fiber, and reducing the inhibition.
DOI: 10.6084/m9.figshare.7244240
title: Air Quality in the Maracanã and Deodoro Zones During the Rio 2016 Olympic Games

description: The air quality during the Summer 2016 Olympic Games in two Olympic zones, Maracanã (Tijuca) and Deodoro, was studied. Volatile organic compounds (VOCs) were collected and analyzed following method TO-15 (United States Environmental Protection Agency), during and in the days after the Games. The total VOC (C4-C12) concentrations were 39.2-160.9 and 36.6-191.4 µg m-3 for Tijuca and Deodoro, respectively. These concentrations were lower than values previously obtained in Tijuca and other areas of the city. VOC speciation and benzene/toluene ratios were also different as a consequence of the restrictions imposed on vehicular transit during the Olympic Games. Concentrations were discussed considering the reactivity and ozone forming potential of individual compounds. Criteria pollutants, determined by the Tijuca Automatic Monitoring Station, were also analyzed. The preventive policies were successful in decreasing the concentrations of CO and PM10, leading to a decrease in mean ozone levels. However, air quality indexes were not dramatically reduced, because of the increase in NOx emissions and isolated events of higher ozone levels.
DOI: 10.7284/135138
title: Multibeam Echosounder data collected during research cruise SKQ201912S using a Kongsberg EM302 instrument system onboard the platform RV Sikuliaq

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7244237.v1
title: Effects of pre-treatment of Curauá fibers on compatibility with portland cements

description: ABSTRACT There has been ever growing interest in the construction industry in using lighter, eco-friendly and sustainable materials, while maintainingthe desirable mechanical properties. The objective of the present work was to evaluate the effects of pre-treatments on chemical compatibility between Curauá fiber (Ananas erectifolius) and Portland cement. In the inhibition test, cement hydration temperature evolution wasmeasured in the absence and presence of untreated and treated Curauá fibers (cold water, hot water and NaOH). The chemical characterization of untreated Curauá fibers was done by determining the content of extractives, lignin, holocellulose and ashes. Thee Segal's method was used for determinate the crystallinity index on untreated and treated fibers. The inhibition test graded the untreated fiber as high inhibition, showing the need to provide it a treatment. Treatments done on Curauá fibers removed some amorphous components of the fibers affected positively the compatibility between cement and fiber, and reducing the inhibition.
DOI: 10.6084/m9.figshare.7244240.v1
title: Air Quality in the Maracanã and Deodoro Zones During the Rio 2016 Olympic Games

description: The air quality during the Summer 2016 Olympic Games in two Olympic zones, Maracanã (Tijuca) and Deodoro, was studied. Volatile organic compounds (VOCs) were collected and analyzed following method TO-15 (United States Environmental Protection Agency), during and in the days after the Games. The total VOC (C4-C12) concentrations were 39.2-160.9 and 36.6-191.4 µg m-3 for Tijuca and Deodoro, respectively. These concentrations were lower than values previously obtained in Tijuca and other areas of the city. VOC speciation and benzene/toluene ratios were also different as a consequence of the restrictions imposed on vehicular transit during the Olympic Games. Concentrations were discussed considering the reactivity and ozone forming potential of individual compounds. Criteria pollutants, determined by the Tijuca Automatic Monitoring Station, were also analyzed. The preventive policies were successful in decreasing the concentrations of CO and PM10, leading to a decrease in mean ozone levels. However, air quality indexes were not dramatically reduced, because of the increase in NOx emissions and isolated events of higher ozone levels.
DOI: 10.6084/m9.figshare.7244231
title: PROGNOSIS OF THE DIAMETER DISTRIBUTION AND CARBON STOCK IN A SECONDARY ATLANTIC FOREST BY MARKOV CHAIN

description: ABSTRACT Growth and yield modeling at the diameter distribution level is an important tool to understand forest dynamics and to predict whether a forest will act as a CO2 emissions source or sink. Therefore, the objective of the present study was to determine the diameter distribution and carbon stock of a forest fragment using the Markov chain to evaluate the impact of growth dynamics on forest carbon capture. Twenty plots of 10x50m were inventoried, between 2010 and 2015, counting the stems with dbh &gt; 5 cm. Diameter distribution was projected for 2015 and 2020, considering the whole fragment and the ecological groups (pioneer and non-pioneer tree species). The volume was determined using allometric equation while biomass and carbon was determined by multiplying the volume by the basic wood density and the carbon content, respectively. The diameter distribution estimated for the fragment and ecological groups did not differ statistically from the values observed using the Kolmogorov-Smirnov test (p-value &lt; 0.05). The number of stems ha-1 estimated in the fragment was from 1,692 in 2015 to 1,841 in 2020. For the pioneer and non-pioneer species, the number of stems ha-1 was from 476 and 1,203 in 2015 to 472 and 1,362 in 2020, respectively. The carbon stock increased 5.69 MgC ha-1, with the greater contribution coming from the non-pioneer species. Therefore, it was concluded that the diameter distribution would remain “J-inverted” and the forest fragment would continue to act as a carbon sink over the coming years.
DOI: 10.7284/135139
title: Multibeam Echosounder data collected during research cruise SKQ201912S using a Kongsberg EM302 instrument system onboard the platform RV Sikuliaq

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7244231.v1
title: PROGNOSIS OF THE DIAMETER DISTRIBUTION AND CARBON STOCK IN A SECONDARY ATLANTIC FOREST BY MARKOV CHAIN

description: ABSTRACT Growth and yield modeling at the diameter distribution level is an important tool to understand forest dynamics and to predict whether a forest will act as a CO2 emissions source or sink. Therefore, the objective of the present study was to determine the diameter distribution and carbon stock of a forest fragment using the Markov chain to evaluate the impact of growth dynamics on forest carbon capture. Twenty plots of 10x50m were inventoried, between 2010 and 2015, counting the stems with dbh &gt; 5 cm. Diameter distribution was projected for 2015 and 2020, considering the whole fragment and the ecological groups (pioneer and non-pioneer tree species). The volume was determined using allometric equation while biomass and carbon was determined by multiplying the volume by the basic wood density and the carbon content, respectively. The diameter distribution estimated for the fragment and ecological groups did not differ statistically from the values observed using the Kolmogorov-Smirnov test (p-value &lt; 0.05). The number of stems ha-1 estimated in the fragment was from 1,692 in 2015 to 1,841 in 2020. For the pioneer and non-pioneer species, the number of stems ha-1 was from 476 and 1,203 in 2015 to 472 and 1,362 in 2020, respectively. The carbon stock increased 5.69 MgC ha-1, with the greater contribution coming from the non-pioneer species. Therefore, it was concluded that the diameter distribution would remain “J-inverted” and the forest fragment would continue to act as a carbon sink over the coming years.
DOI: 10.6084/m9.figshare.7244234
title: Best practices for pervious concrete mix design and laboratory tests

description: Abstract Pervious concrete may be used for stormwater management since it allows the water to pass through its interconnected macropores into stormwater systems or soils below. However, there is a need for additional standards related to pervious concrete prior to its widespread use, and there are many aspects related to mix design for desired properties, compaction methods, and test procedures that are not yet completely understood. These variables may significantly affect the functional and mechanical performance of the material. In this paper, mix designs and test specimen preparation techniques were evaluated. The IBRACON method for mixture design was used to obtain the mixture proportions and the calculated density for the desired porosity of 25%. In addition, two different types of specimens (cast or cored) and compaction methods (roller or Proctor hammer compacted) were performed. The density of each specimen was controlled to obtain the same calculated density. Several tests were conducted to compare the following variables: density, porosity, surface infiltration rate, permeability and compressive strength. Additionally, the effects of mortar capping versus neoprene-rubber caps on compressive strength measurements of pervious concrete were evaluated. The experimental results showed that cast specimens have more consistent results than cores. The design method studied with strict control of density was efficient to obtain the desired porosity mainly for cast specimens. The roller leads to a more compacted top surface resulting in a decrease in the infiltration rate and permeability of the cores. The mortar capping method is more consistent than the other.
DOI: 10.6084/m9.figshare.7244225
title: Influence of packaging on the quality of Brazil nuts

description: ABSTRACT The Brazil nut is an important commodity that grows in the Amazon rainforest and is notable for its high nutritional value. However, the effect that packaging has on product shelf-life is unclear. This study evaluated the microbiological and nutritional quality of unshelled Brazil nuts packed in (a) nylon and polypropylene under vacuum, and (b) in polyethylene terephthalate and polyethylene aluminized films. The nuts were stored for nine months under natural environmental conditions. The most probable number of total and thermotolerant coliforms and Escherichia coli, and counting of molds and yeast were determined in the unshelled nuts shortly after collection and every three months during storage. Moisture, lipids, ash, neutral detergent fiber, and acid detergent fiber contents were measured by the gravimetric method. Crude protein content was measured using the Kjeldahl method. Coliform levels were within legislated standards in both types of packaging. Mold and yeast growth increased with time in both types of packaging (0.1x10¹ to 9.5x10³ colony forming units g-1), but only nuts packaged in aluminum film showed a significant increase after six months of storage. After nine months of storage, both types of packaged nuts had good nutritional quality. Aluminized packaging resulted in better conservation of the lipid fraction and lower permeability to water vapor, however, vacuum packaging was more effective in controlling fungal growth, possibly due to the lack of oxygen.
DOI: 10.6084/m9.figshare.7244234.v1
title: Best practices for pervious concrete mix design and laboratory tests

description: Abstract Pervious concrete may be used for stormwater management since it allows the water to pass through its interconnected macropores into stormwater systems or soils below. However, there is a need for additional standards related to pervious concrete prior to its widespread use, and there are many aspects related to mix design for desired properties, compaction methods, and test procedures that are not yet completely understood. These variables may significantly affect the functional and mechanical performance of the material. In this paper, mix designs and test specimen preparation techniques were evaluated. The IBRACON method for mixture design was used to obtain the mixture proportions and the calculated density for the desired porosity of 25%. In addition, two different types of specimens (cast or cored) and compaction methods (roller or Proctor hammer compacted) were performed. The density of each specimen was controlled to obtain the same calculated density. Several tests were conducted to compare the following variables: density, porosity, surface infiltration rate, permeability and compressive strength. Additionally, the effects of mortar capping versus neoprene-rubber caps on compressive strength measurements of pervious concrete were evaluated. The experimental results showed that cast specimens have more consistent results than cores. The design method studied with strict control of density was efficient to obtain the desired porosity mainly for cast specimens. The roller leads to a more compacted top surface resulting in a decrease in the infiltration rate and permeability of the cores. The mortar capping method is more consistent than the other.
DOI: 10.7284/135128
title: Radiometer data collected during research cruise SKQ201912S using a RMR Co. PRP instrument system onboard the platform RV Sikuliaq

description: Original (unprocessed) data collected during a Field_expedition
DOI: 10.6084/m9.figshare.7244228
title: ASSOCIATION BETWEEN PERCEPTION OF SLEEP QUALITY AND ASSIMILATION OF CONTENT COVERED IN CLASS

description: ABSTRACT Objective: To analyze the association between self-perception of sleep quality and assimilation of content covered in classes by adolescents. Methods: Epidemiological cross-sectional study conducted with 481 high-school students (14 to 19 years), both genders, enrolled in public schools in the city of Caruaru, Pernambuco, and selected by random cluster sampling strategy. Analyses were conducted using the Chi-square test and binary logistic regression. Results: 44.1% of the adolescents reported learning difficulties during classes, 77.1% slept less than eight hours per day, and 28.9% had a bad perception of their sleep quality. Young people who studied at least one extra hour per day out of school had less difficulty in assimilating class content (OR=0.34; 95%CI 0.19-0.58). We also found that participants who reported a bad perception of sleep quality were more likely to have learning difficulties at school (OR=1.73; 95%CI 1.13-2.65) regardless of gender, age, school shift, study time out of school, and sleeping hours. Conclusions: Perception of sleep quality was associated with learning difficulties at school regardless of the number of sleeping and study hours.
DOI: 10.6084/m9.figshare.7244222
title: Influence of physical-chemical parameters on the composition of toxic constituents in landfill leachate

description: ABSTRACT The characterization of leachate generated in landfills can clarify the degradation phenomena that occur inside the waste cells and indirectly indicate their toxic potential. The objective of this study was to evaluate the influence of physical and chemical parameters on toxic components, such as metals and total ammonia nitrogen (TAN), found in the leachate generated by a cell from the Sanitary Landfill in Campina Grande, Paraíba. pH, volatile fatty acids (VFA), total alkalinity (AT), chlorides, chemical oxygen demand (COD), TAN and metals (Pb, Cr, Co, Ni, Fe and Mn) were investigated. The results showed that during the acid fermentation phase a high production of VFA occurred in the landfilled waste mass, which maintained the values of pH below neutrality and contributed for high concentrations of COD, chlorides and a higher toxicity in the leachate compared with the analyzed metals. However, in the case of methanogenic conditions, a decrease in the VFA contents was observed and, with this, the pH tended to be basicity, making the medium more alkaline, favoring the precipitation of the studied metals, but contributing to the high levels of TAN. It is possible to conclude that pH and VFA had a strong influence on the metals (Pb, Cr, Co, Ni, Fe and Mn) and TAN during the 150 days of evaluation.
DOI: 10.6084/m9.figshare.7244225.v1
title: Influence of packaging on the quality of Brazil nuts

description: ABSTRACT The Brazil nut is an important commodity that grows in the Amazon rainforest and is notable for its high nutritional value. However, the effect that packaging has on product shelf-life is unclear. This study evaluated the microbiological and nutritional quality of unshelled Brazil nuts packed in (a) nylon and polypropylene under vacuum, and (b) in polyethylene terephthalate and polyethylene aluminized films. The nuts were stored for nine months under natural environmental conditions. The most probable number of total and thermotolerant coliforms and Escherichia coli, and counting of molds and yeast were determined in the unshelled nuts shortly after collection and every three months during storage. Moisture, lipids, ash, neutral detergent fiber, and acid detergent fiber contents were measured by the gravimetric method. Crude protein content was measured using the Kjeldahl method. Coliform levels were within legislated standards in both types of packaging. Mold and yeast growth increased with time in both types of packaging (0.1x10¹ to 9.5x10³ colony forming units g-1), but only nuts packaged in aluminum film showed a significant increase after six months of storage. After nine months of storage, both types of packaged nuts had good nutritional quality. Aluminized packaging resulted in better conservation of the lipid fraction and lower permeability to water vapor, however, vacuum packaging was more effective in controlling fungal growth, possibly due to the lack of oxygen.