cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.5671498
title: Transverse permeability determination and influence in resin flow through an orthotropic medium in the RTM process

description: ABSTRACT Resin Transfer Molding (RTM) process is commonly used to produce high quality polymeric composites with simple or complex geometries in small to large sizes. In RTM process a preformed reinforcement is positioned inside the mold cavity. This dry reinforcement is actually a fibrous porous media whereby resin will flow. The mold is then closed and resin is injected. After complete impregnation of the reinforcement, resin cure process takes place. Numerical simulation is a very useful tool for mold design and process optimization, however resin and reinforced medium physical properties must be precisely determined. Medium permeability is probably the most important and most difficult parameter to be evaluated. In this work it is proposed a numerical/experimental methodology to determine transverse permeability in reinforcements used within RTM process. PAM-RTM software was chosen to simulate resin flow through the reinforced medium. Proposed methodology uses the inverse parameter estimation method to calculate the unknown permeability. Newton-Raphson method was used to solve the associated algebraic equation system, on which PAM-RTM software is used to calculate resin injection times. Results have shown that with previous knowledge (taken from literature or obtained experimentally) of the in-plane permeabilities ( Kxx and Kyy ), physical properties of the resin (ρ, µ), medium porosity (ε) and total filling time (t) it is possible to estimate transverse permeability in thick pieces. It was also performed a numerical study about the influence of transverse permeability in resin flow inside the mold. This study predicted several possible problems that may occur when transverse permeability is much smaller than in-plane permeabilities. Finally, it is possible to state that mold design and proper fibrous reinforcement choice can be optimized when numerical techniques are used.
DOI: 10.6084/m9.figshare.5671498.v1
title: Transverse permeability determination and influence in resin flow through an orthotropic medium in the RTM process

description: ABSTRACT Resin Transfer Molding (RTM) process is commonly used to produce high quality polymeric composites with simple or complex geometries in small to large sizes. In RTM process a preformed reinforcement is positioned inside the mold cavity. This dry reinforcement is actually a fibrous porous media whereby resin will flow. The mold is then closed and resin is injected. After complete impregnation of the reinforcement, resin cure process takes place. Numerical simulation is a very useful tool for mold design and process optimization, however resin and reinforced medium physical properties must be precisely determined. Medium permeability is probably the most important and most difficult parameter to be evaluated. In this work it is proposed a numerical/experimental methodology to determine transverse permeability in reinforcements used within RTM process. PAM-RTM software was chosen to simulate resin flow through the reinforced medium. Proposed methodology uses the inverse parameter estimation method to calculate the unknown permeability. Newton-Raphson method was used to solve the associated algebraic equation system, on which PAM-RTM software is used to calculate resin injection times. Results have shown that with previous knowledge (taken from literature or obtained experimentally) of the in-plane permeabilities ( Kxx and Kyy ), physical properties of the resin (ρ, µ), medium porosity (ε) and total filling time (t) it is possible to estimate transverse permeability in thick pieces. It was also performed a numerical study about the influence of transverse permeability in resin flow inside the mold. This study predicted several possible problems that may occur when transverse permeability is much smaller than in-plane permeabilities. Finally, it is possible to state that mold design and proper fibrous reinforcement choice can be optimized when numerical techniques are used.
DOI: 10.6084/m9.figshare.5671495
title: DMTA - octa-POSS

description: DMTA - increasing octa-POSS content<br>
DOI: 10.6084/m9.figshare.5671495.v1
title: DMTA - octa-POSS

description: DMTA - increasing octa-POSS content<br>
DOI: 10.6084/m9.figshare.5671489
title: Effect of the chemical attack on the properties of cimentititous composites with partial substitution of ash from sugar cane bagasse in natura

description: ABSTRACT Seeking the reutilization of waste from agriculture and urban sources, studies have presented an option in the inclusion of such waste into new low-cost materials that are environmentally viable. One possibility is the reutilization of sugarcane bagasse ashes (SBA), the final waste in the productive process of the Brazilian alcohol sector. In addition to the behavior of materials with the use of SBA as additions in cement-based materials under normal environmental conditions, the study of the behavior of these materials when exposed to harsh environments is required. Thus, this project evaluated the properties, the compression strength and the bulk density of cement composites with partial replacement of cement by SBA without prior treatment. Also, it analyzed the weight loss and compressive strength of the composites subjected to environments with the presence of chloride ions. A factorial design was adopted to verify the influence of the addition of SBA (5wt%, 10wt% and 15wt%) and water/cement ratio (0.45 and 0.55) in the studied properties. The interaction between the factors was significant. The values obtained from the compressive strength of the manufactured composites showed that it is possible to replace up to 15wt% of cement for in natura SBA. After a chemical attack with an acid solution of HCl 30%, it could be observed that all materials had a lower compressive strength, which can be explained by the high weight loss suffered by all composites. Based on the results of compressive resistance, density and weight loss after the attack, it was observed that the mechanical behavior of the composites in relation to the referential conditions were similar. This study showed that it is feasible, in accordance to the studied properties, to use these composites in promoting the partial replacement of cement by this type of waste and its reutilization.
DOI: 10.6084/m9.figshare.5671489.v1
title: Effect of the chemical attack on the properties of cimentititous composites with partial substitution of ash from sugar cane bagasse in natura

description: ABSTRACT Seeking the reutilization of waste from agriculture and urban sources, studies have presented an option in the inclusion of such waste into new low-cost materials that are environmentally viable. One possibility is the reutilization of sugarcane bagasse ashes (SBA), the final waste in the productive process of the Brazilian alcohol sector. In addition to the behavior of materials with the use of SBA as additions in cement-based materials under normal environmental conditions, the study of the behavior of these materials when exposed to harsh environments is required. Thus, this project evaluated the properties, the compression strength and the bulk density of cement composites with partial replacement of cement by SBA without prior treatment. Also, it analyzed the weight loss and compressive strength of the composites subjected to environments with the presence of chloride ions. A factorial design was adopted to verify the influence of the addition of SBA (5wt%, 10wt% and 15wt%) and water/cement ratio (0.45 and 0.55) in the studied properties. The interaction between the factors was significant. The values obtained from the compressive strength of the manufactured composites showed that it is possible to replace up to 15wt% of cement for in natura SBA. After a chemical attack with an acid solution of HCl 30%, it could be observed that all materials had a lower compressive strength, which can be explained by the high weight loss suffered by all composites. Based on the results of compressive resistance, density and weight loss after the attack, it was observed that the mechanical behavior of the composites in relation to the referential conditions were similar. This study showed that it is feasible, in accordance to the studied properties, to use these composites in promoting the partial replacement of cement by this type of waste and its reutilization.
DOI: 10.6084/m9.figshare.5671486
title: Effect of natural ageing on the properties of recycled polypropylene/ethylene vinyl acetate/wood flour composites

description: ABSTRACT Wood flour composites main applications are represented by outdoor furnishing. Therefore, it is important to evaluate their behavior under natural ageing conditions. This work aims to investigate the natural ageing impact on the mechanical, physical, thermal e morphological properties of recycled polypropylene/ethylene vinyl acetate/wood flour composites (PP/EVA/ITA). Samples were exposed to natural ageing for 12 months in Porto Alegre (BR). Mezilaurus itauba (ITA) wood flour was used at 30 % w/w. Results showed that PP filled wood flour retained a higher fraction of the original mechanical properties after natural ageing. Crystallinity degree for composites increased from 30.9 up to 37.5% Climatic conditions affected the colorimetric and morphological characteristics of composites, indicating that there was not only photo-degradation but also thermo-oxidative and hydrolytic degradation. In this way, the use of antioxidant additives and UV photo-absorbers is recommended to avoid stress-cracking, discoloration and loss the mechanical properties.
DOI: 10.6084/m9.figshare.5671483
title: Journals scientific of Agrarian Sciences: analysis of the Brazilian titles indexd in the Web of Science and Scopus

description: ABSTRACT This research studies the characteristics of the p journals Brazilians of the large area of Agrarian Sciences indexed in the Web of specific objective Science and Scopus. The specific objectives are: a) To identify the journals Brazilians of the large area of Agrarian Sciences defined by the CAPES; b) To describe the characteristics of the journals ones: year of creation; entity publishing company; quality indicators; accepted idioms; regularity; platforms; persistent identification; e c) To identify to the sponsorship and the model of financing of the journals ones. The methodology used for the research is characterized as bibliographical, documental, descriptive and exploratória, with quali-quantitative analysis. The corpus of the study is journals the scientific Brazilians registered in the WebQualis of the large area of Agrarian Sciences, defined for the CAPES and indexd in the WoS and resulted Scopus.O it identified 74 you search, 71 in open access and three for subscription. All the 74 periodic are indexed in the Scopus and 44 together between the Scopus and WoS . The main publishing entities are the universities, which maintain 50 % (37) of journals, resulted from the associations with 32,4 % (24), institutes of inquiry with 13,5 % (10), and a commercial publisher with 4,1 % (3). One checks that no journals is a Qualis A1 and the predominance of the titles they are in the stratum B1, with 43,2 % (32) you search. As for the financing model, 56,8 % (42) journals adopt the golden road and 29,7 % (32) of the titles follow the Platine road.
DOI: 10.6084/m9.figshare.5671483.v1
title: Journals scientific of Agrarian Sciences: analysis of the Brazilian titles indexd in the Web of Science and Scopus

description: ABSTRACT This research studies the characteristics of the p journals Brazilians of the large area of Agrarian Sciences indexed in the Web of specific objective Science and Scopus. The specific objectives are: a) To identify the journals Brazilians of the large area of Agrarian Sciences defined by the CAPES; b) To describe the characteristics of the journals ones: year of creation; entity publishing company; quality indicators; accepted idioms; regularity; platforms; persistent identification; e c) To identify to the sponsorship and the model of financing of the journals ones. The methodology used for the research is characterized as bibliographical, documental, descriptive and exploratória, with quali-quantitative analysis. The corpus of the study is journals the scientific Brazilians registered in the WebQualis of the large area of Agrarian Sciences, defined for the CAPES and indexd in the WoS and resulted Scopus.O it identified 74 you search, 71 in open access and three for subscription. All the 74 periodic are indexed in the Scopus and 44 together between the Scopus and WoS . The main publishing entities are the universities, which maintain 50 % (37) of journals, resulted from the associations with 32,4 % (24), institutes of inquiry with 13,5 % (10), and a commercial publisher with 4,1 % (3). One checks that no journals is a Qualis A1 and the predominance of the titles they are in the stratum B1, with 43,2 % (32) you search. As for the financing model, 56,8 % (42) journals adopt the golden road and 29,7 % (32) of the titles follow the Platine road.
DOI: 10.6084/m9.figshare.5671480
title: Unsaturated polyester composite reinforced with Caroá fiber (Neoglaziovia Variegate): water sorption and mechanical properties

description: ABSTRACT Aiming to minimize the environmental pollution and reducing the production costs of the composite materials, the use of plant fibers improves their physical and mechanical properties. On the other hand, fibers have high water absorption, which may increase their volume and weaken the fiber/matrix interaction, affecting the mechanical features of the composites. Concerned with this problem, this research had the objective of making 3 and 10 millimeter-thick specimens, containing 23% (m/m) of Caroa fibers and 73% (m/m) of unsaturated polyester. Samples were withdrawn after 0, 2, 4, 7, 12 and 21 days of exposure at room temperature water (ASTM D570 − 98). Then, the test of tensile (ASTM D 3039), flexural (ASTM D 790-03) and impact (ASTM D 256) was realized and the mechanical properties were analyzed. The samples subjected to humidity had their fibers degraded and presented loss of mechanical properties, more significant in composite with 3 mm. For example, the reduction of the strengths tensile, after 21 days of test were 80% for composites with 3 mm and 60% for composites with 10 mm. Studies like this are important for long-term applications of such composites in humid environments.
DOI: 10.6084/m9.figshare.5671480.v1
title: Unsaturated polyester composite reinforced with Caroá fiber (Neoglaziovia Variegate): water sorption and mechanical properties

description: ABSTRACT Aiming to minimize the environmental pollution and reducing the production costs of the composite materials, the use of plant fibers improves their physical and mechanical properties. On the other hand, fibers have high water absorption, which may increase their volume and weaken the fiber/matrix interaction, affecting the mechanical features of the composites. Concerned with this problem, this research had the objective of making 3 and 10 millimeter-thick specimens, containing 23% (m/m) of Caroa fibers and 73% (m/m) of unsaturated polyester. Samples were withdrawn after 0, 2, 4, 7, 12 and 21 days of exposure at room temperature water (ASTM D570 − 98). Then, the test of tensile (ASTM D 3039), flexural (ASTM D 790-03) and impact (ASTM D 256) was realized and the mechanical properties were analyzed. The samples subjected to humidity had their fibers degraded and presented loss of mechanical properties, more significant in composite with 3 mm. For example, the reduction of the strengths tensile, after 21 days of test were 80% for composites with 3 mm and 60% for composites with 10 mm. Studies like this are important for long-term applications of such composites in humid environments.
DOI: 10.6084/m9.figshare.5671474
title: Impactos Econômicos do Aumento das Exportações Brasileiras de Produtos Agrícolas e Agroindustriais para Diferentes Destinos

description: Abstract: Brazilian export agribusiness activities are considered strategic to the Brazilian trade policy because, besides the contribution to the trade surplus and economic growth in the country, these activities reveal a high degree of insertion in the international trade, both by the number of existing traditional markets and by the capacity to explore new potential markets. Thus, this study analyzes the probable effects of an external demand expansion for agricultural and agroindustrial products in some traditional and potential market, using a Computable General Equilibrium (CGE) model for Brazil, LATES-BR, calibrated to 2011. The projections allow us to do a quantitative assessment of the relative importance of the Brazilian agribusiness traditional and potential markets and it contributes to the ongoing debate of the National Export Plan (PNE). The impacts size of the potential markets, especially countries in South America, when compared with traditional markets, such as the United States of America, is much lower. However, as discussed in our study, the most important issue is not the impact size, but the movement in macroeconomic terms and the trade results, i.e. the potential to explore new markets as an alternative to increase the Brazilian share in the international trade.
DOI: 10.6084/m9.figshare.5671474.v1
title: Impactos Econômicos do Aumento das Exportações Brasileiras de Produtos Agrícolas e Agroindustriais para Diferentes Destinos

description: Abstract: Brazilian export agribusiness activities are considered strategic to the Brazilian trade policy because, besides the contribution to the trade surplus and economic growth in the country, these activities reveal a high degree of insertion in the international trade, both by the number of existing traditional markets and by the capacity to explore new potential markets. Thus, this study analyzes the probable effects of an external demand expansion for agricultural and agroindustrial products in some traditional and potential market, using a Computable General Equilibrium (CGE) model for Brazil, LATES-BR, calibrated to 2011. The projections allow us to do a quantitative assessment of the relative importance of the Brazilian agribusiness traditional and potential markets and it contributes to the ongoing debate of the National Export Plan (PNE). The impacts size of the potential markets, especially countries in South America, when compared with traditional markets, such as the United States of America, is much lower. However, as discussed in our study, the most important issue is not the impact size, but the movement in macroeconomic terms and the trade results, i.e. the potential to explore new markets as an alternative to increase the Brazilian share in the international trade.
DOI: 10.6084/m9.figshare.5671468
title: DSC- octa POSS

description: DSC data, increasing octa-POSS content<br>
DOI: 10.6084/m9.figshare.5671468.v1
title: DSC- octa POSS

description: DSC data, increasing octa-POSS content<br>
DOI: 10.6084/m9.figshare.5671465
title: Dipyridamole potentiated the trypanocidal effect of nifurtimox and improved the cardiac function in NMRI mice with acute chagasic myocarditis

description: BACKGROUND As chronic Chagas disease does not have a definitive treatment, the development of alternative therapeutic protocols is a priority. Dipyridamole (DPY) is an alternative to counteract the pathophysiological phenomena involved in Chagas cardiomyopathy. OBJECTIVE To evaluate the therapeutic efficacy of DPY associated with nifurtimox (Nfx) in epimastigote axenic cultures and in mice with acute Chagas disease. METHODS NMRI adult male mice were divided into nine groups: three healthy and six Trypanosoma cruzi-infected groups. Mice received vehicle, Nfx or DPY, alone or combined. The doses assayed were Nfx 10 and 40 mg/kg and DPY 30 mg/kg. The treatment efficacy was evaluated by clinical, electrocardiographic, parasitological, biochemical and histopathological methods. FINDINGS In vitro, DPY and Nfx had a trypanocidal effect with IC50 values of 372 ± 52 and 21.53 ± 2.13 µM, respectively; DPY potentiated the Nfx effect. In vivo, Nfx (40 mg/kg) with or without DPY had a therapeutic effect, which was reflected in the 84-92% survival rate and elimination of parasitaemia and heart tissue amastigotes. Nfx (10 mg/kg) had a subtherapeutic effect with no survival and persistence of amastigotes, inflammation and fibrosis in heart tissue; adding DPY increased the survival rate to 85%, and all tested parameters were significantly improved. MAIN CONCLUSION DPY has a trypanocidal effect in vitro and enhances the Nfx therapeutic effect in an in vivo murine model.
DOI: 10.6084/m9.figshare.5671465.v1
title: Dipyridamole potentiated the trypanocidal effect of nifurtimox and improved the cardiac function in NMRI mice with acute chagasic myocarditis

description: BACKGROUND As chronic Chagas disease does not have a definitive treatment, the development of alternative therapeutic protocols is a priority. Dipyridamole (DPY) is an alternative to counteract the pathophysiological phenomena involved in Chagas cardiomyopathy. OBJECTIVE To evaluate the therapeutic efficacy of DPY associated with nifurtimox (Nfx) in epimastigote axenic cultures and in mice with acute Chagas disease. METHODS NMRI adult male mice were divided into nine groups: three healthy and six Trypanosoma cruzi-infected groups. Mice received vehicle, Nfx or DPY, alone or combined. The doses assayed were Nfx 10 and 40 mg/kg and DPY 30 mg/kg. The treatment efficacy was evaluated by clinical, electrocardiographic, parasitological, biochemical and histopathological methods. FINDINGS In vitro, DPY and Nfx had a trypanocidal effect with IC50 values of 372 ± 52 and 21.53 ± 2.13 µM, respectively; DPY potentiated the Nfx effect. In vivo, Nfx (40 mg/kg) with or without DPY had a therapeutic effect, which was reflected in the 84-92% survival rate and elimination of parasitaemia and heart tissue amastigotes. Nfx (10 mg/kg) had a subtherapeutic effect with no survival and persistence of amastigotes, inflammation and fibrosis in heart tissue; adding DPY increased the survival rate to 85%, and all tested parameters were significantly improved. MAIN CONCLUSION DPY has a trypanocidal effect in vitro and enhances the Nfx therapeutic effect in an in vivo murine model.
DOI: 10.6084/m9.figshare.5671462
title: Nitrogen Transfer from Cover Crop Residues to Onion Grown under Minimum Tillage in Southern Brazil

description: ABSTRACT Nitrogen derived from cover crop residues may contribute to the nutrition of onion grown under minimum tillage (MT) and cultivated in rotation. The aim of this study was to evaluate the N transferred from different cover crop residues to the onion crop cultivated under MT in southern Brazil. In June 2014, oilseed radish, black oat, and oilseed radish + black oat residues labeled with 15N were deposited on the soil surface before transplanting onions. During the growth season and at harvest, young expanded onion leaves, complete plants, and samples from different soil layers were collected and analyzed for recovery of 15N-labeled residue. Oilseed radish decomposed faster than other residues and 4 % of residue N was recovered in leaves and bulbs at harvest, but in general, N in plant organs was derived from sources other than the cover crop residues. In addition, leaf N was in the proper range for all treatments and was adequately mobilized to the bases for bulbing. The N derived from decomposing residues contributed little to onion development and the use of these plants should be chosen based on their advantages for physical and biological soil quality.