cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14321749
title: Stabilized Guabirotuba Silt with waste from cellulose and paper industry

description: ABSTRACT The unconfined compressive strength, the splitting tensile strength and the California Bearing Ratio (CBR) were systematically investigated to analyze the performance of a silt soil from the metropolitan region of Curitiba (Brazil) stabilized with cellulose ash and with hydrated dolomitic lime. A series of compaction tests on normal Proctor energy were performed to calculate the optimum compaction parameters of the soil- cellulose ash-lime mixtures: maximum dry unit weight (γd-max) and optimum moisture content (ωo). Four percentages of cellulose ash (5%, 10%, 15% and 20% in relation to the dry mass of the soil) were added and used, and a fixed content of lime (L) of 5% based on the modified initial consumption of lime and established from the interpretation of pH measurements performed on several soil-ash-lime mixtures. The results demonstrate that there is an increase in the optimum moisture content and a decrease in the maximum dry unit weight of the compaction curves with increasing the cellulose ash content. On the other hand, the tests of unconfined compression, splitting tensile and CBR show that there is an increase in the mechanical strength values of the blends up to an optimal content of 15%. In addition, Energy Dispersion Spectroscopy (EDS) made in a prototype blend shows that there was a chemical interaction between soil, lime and the smallest particles of cellulose ash. Finally, dosing equations that allow estimation of the strength values of the blends were developed based on porosity/lime index (η/Liv) considering the specific gravity and volume of the materials besides the compaction energy.
DOI: 10.6084/m9.figshare.14321749.v1
title: Stabilized Guabirotuba Silt with waste from cellulose and paper industry

description: ABSTRACT The unconfined compressive strength, the splitting tensile strength and the California Bearing Ratio (CBR) were systematically investigated to analyze the performance of a silt soil from the metropolitan region of Curitiba (Brazil) stabilized with cellulose ash and with hydrated dolomitic lime. A series of compaction tests on normal Proctor energy were performed to calculate the optimum compaction parameters of the soil- cellulose ash-lime mixtures: maximum dry unit weight (γd-max) and optimum moisture content (ωo). Four percentages of cellulose ash (5%, 10%, 15% and 20% in relation to the dry mass of the soil) were added and used, and a fixed content of lime (L) of 5% based on the modified initial consumption of lime and established from the interpretation of pH measurements performed on several soil-ash-lime mixtures. The results demonstrate that there is an increase in the optimum moisture content and a decrease in the maximum dry unit weight of the compaction curves with increasing the cellulose ash content. On the other hand, the tests of unconfined compression, splitting tensile and CBR show that there is an increase in the mechanical strength values of the blends up to an optimal content of 15%. In addition, Energy Dispersion Spectroscopy (EDS) made in a prototype blend shows that there was a chemical interaction between soil, lime and the smallest particles of cellulose ash. Finally, dosing equations that allow estimation of the strength values of the blends were developed based on porosity/lime index (η/Liv) considering the specific gravity and volume of the materials besides the compaction energy.
DOI: 10.6084/m9.figshare.14321751
title: Thermoenergetic and luminous performance of a office building with the use of electrochromic glasses

description: ABSTRACT This work aims to analyze the thermoenergetic and luminous performance of a building with office characteristic activities with electrochromic glasses through comparative study, considering common glasses of 3mm and 6mm. For the computational simulation were used the EnergyPlus software. Simulations were performed with the Clear common glass Clear of 3 mm and 6 mm and the electrochromic glass Sage Glass 9 mm with the purpose of analyzing the lighting, the energy consumption, and the level of thermal comfort coming from the artificial climatization and the natural ventilation, respectively. The simulations were performed in two bioclimatic zones, in bioclimatic zone 2 (ZB 2) and in bioclimatic zone 8 (ZB 8), where it was used the climate files from the city of Camaquã and the city of Manaus, respectively. With the results obtained it was possible to observe that the building with electrochromic glasses presented the best level of thermal comfort in the hours occupied, and that the energy consumption for cooling decreases as the coloration increases, especially in the ZB 8, since it is a region of warm weather. It was noted that in the ZB 2 in some months of the year, the electrochromic glass remains totally discolored, since the temperature of setpoint was always higher than the external temperature. It was also possible to observe that it is fundamental analyze the solar orientation for the best positioning of the building’s openings.
DOI: 10.6084/m9.figshare.14321751.v1
title: Thermoenergetic and luminous performance of a office building with the use of electrochromic glasses

description: ABSTRACT This work aims to analyze the thermoenergetic and luminous performance of a building with office characteristic activities with electrochromic glasses through comparative study, considering common glasses of 3mm and 6mm. For the computational simulation were used the EnergyPlus software. Simulations were performed with the Clear common glass Clear of 3 mm and 6 mm and the electrochromic glass Sage Glass 9 mm with the purpose of analyzing the lighting, the energy consumption, and the level of thermal comfort coming from the artificial climatization and the natural ventilation, respectively. The simulations were performed in two bioclimatic zones, in bioclimatic zone 2 (ZB 2) and in bioclimatic zone 8 (ZB 8), where it was used the climate files from the city of Camaquã and the city of Manaus, respectively. With the results obtained it was possible to observe that the building with electrochromic glasses presented the best level of thermal comfort in the hours occupied, and that the energy consumption for cooling decreases as the coloration increases, especially in the ZB 8, since it is a region of warm weather. It was noted that in the ZB 2 in some months of the year, the electrochromic glass remains totally discolored, since the temperature of setpoint was always higher than the external temperature. It was also possible to observe that it is fundamental analyze the solar orientation for the best positioning of the building’s openings.
DOI: 10.6084/m9.figshare.14321752
title: Solid surface composite materials manufactured from syrup of polymethyl methacrylate, alumina trihydrate and natural mineral fillers

description: ABSTRACT A composite material, which properties are similar to the commercial material Krion®, was manufactured using polymethyl methacrylate (PMMA) syrup, alumina trihydrate (ATH) and natural mineral fillers (CMN). For this purpose, composites have been manufactured in 2 stages: In first stage, free radical polymerization of methyl methacrylate (MMA) was carried out to obtain syrup of polymethyl methacrylate. Polymerization parameters were determined in order to avoid autoacceleration effect and to get syrup which PMMA conversion avoids precipitation of ATH particles. In second stage, composite samples were manufactured using the obtained syrup, ATH and CMN particles and, then, they were tested in order to determine suitable parameters to get similar properties to Krion®. It has been proved that syrup must have a MMA to PMMA conversion between 20% and 25% to avoid autoacceleration effect and precipitation of ATH particles. To obtain such syrup, polymerization must be carried out using 0,1% of benzoyl peroxide (PBO) y 0,2% of ethylene glycol dimercaptoacetate (EGDM) at 85°C during 90 minutes. Similarly, to get composites which properties are similar to Krion®, the manufacturing parameters of a PMMA composite reinforced with ATH and CMN particles are: 40% syrup / 60% ATH / %CMN variable according to the type of filler, 0,1% of additional PBO, 2,0% ethylene glycol dimethacrylate (EGDMA) y curing time 13 hours inside a furnace at 85°C. Properties of the composite that has been manufactured under these conditions and only contains ATH filler are: flexural resistance of 53 MPa, flexural elastic modulus of 8054 MPa and hardness of 91 HRM. Esthetic quality improves with the incorporation of CMN but mechanical properties decrease.
DOI: 10.6084/m9.figshare.14321752.v1
title: Solid surface composite materials manufactured from syrup of polymethyl methacrylate, alumina trihydrate and natural mineral fillers

description: ABSTRACT A composite material, which properties are similar to the commercial material Krion®, was manufactured using polymethyl methacrylate (PMMA) syrup, alumina trihydrate (ATH) and natural mineral fillers (CMN). For this purpose, composites have been manufactured in 2 stages: In first stage, free radical polymerization of methyl methacrylate (MMA) was carried out to obtain syrup of polymethyl methacrylate. Polymerization parameters were determined in order to avoid autoacceleration effect and to get syrup which PMMA conversion avoids precipitation of ATH particles. In second stage, composite samples were manufactured using the obtained syrup, ATH and CMN particles and, then, they were tested in order to determine suitable parameters to get similar properties to Krion®. It has been proved that syrup must have a MMA to PMMA conversion between 20% and 25% to avoid autoacceleration effect and precipitation of ATH particles. To obtain such syrup, polymerization must be carried out using 0,1% of benzoyl peroxide (PBO) y 0,2% of ethylene glycol dimercaptoacetate (EGDM) at 85°C during 90 minutes. Similarly, to get composites which properties are similar to Krion®, the manufacturing parameters of a PMMA composite reinforced with ATH and CMN particles are: 40% syrup / 60% ATH / %CMN variable according to the type of filler, 0,1% of additional PBO, 2,0% ethylene glycol dimethacrylate (EGDMA) y curing time 13 hours inside a furnace at 85°C. Properties of the composite that has been manufactured under these conditions and only contains ATH filler are: flexural resistance of 53 MPa, flexural elastic modulus of 8054 MPa and hardness of 91 HRM. Esthetic quality improves with the incorporation of CMN but mechanical properties decrease.
DOI: 10.6084/m9.figshare.14321754
title: Improved fatigue performance of nanostructured bidirectional fiberglass-polyurethane composites under uniaxial state and high deformations

description: ABSTRACT Plates of composite material of bidirectional fiberglass [+/-45]4S and nanostructured polyurethane matrix were manufactured using the Vacuum Assisted Resin Infusion (VARI) technique. Hydrophobic nanosilica (NS) was used at 1 and 2 wt. % loading. Even though the use of NS, the permeability of the perform did not increase substantially, obtaining high Vf (52%) and a good impregnation, as visualized with SEM. Uniaxial tensile tests under quasi-static conditions presented high deformations to failure (emax&gt;10%), tensile strengths (RUTS) and elastic moduli (E) which decreased as a function of increased NS loading. On the other hand, the stress-controlled fatigue testings revealed that the addition of NS up to 2 wt. % improved fatigue performance. Specifically, the a and b constants of the empirical lineal model presented an increase of 77% and 92.7%, respectively. This improvement was corroborated through the measurement of the residual elastic modulus. Finally, the laminates presented an accumulation of inelastic deformation (ratcheting), whereas this phenomena was studied for two frequencies, 0.2Hz and 2 Hz.
DOI: 10.6084/m9.figshare.14321754.v1
title: Improved fatigue performance of nanostructured bidirectional fiberglass-polyurethane composites under uniaxial state and high deformations

description: ABSTRACT Plates of composite material of bidirectional fiberglass [+/-45]4S and nanostructured polyurethane matrix were manufactured using the Vacuum Assisted Resin Infusion (VARI) technique. Hydrophobic nanosilica (NS) was used at 1 and 2 wt. % loading. Even though the use of NS, the permeability of the perform did not increase substantially, obtaining high Vf (52%) and a good impregnation, as visualized with SEM. Uniaxial tensile tests under quasi-static conditions presented high deformations to failure (emax&gt;10%), tensile strengths (RUTS) and elastic moduli (E) which decreased as a function of increased NS loading. On the other hand, the stress-controlled fatigue testings revealed that the addition of NS up to 2 wt. % improved fatigue performance. Specifically, the a and b constants of the empirical lineal model presented an increase of 77% and 92.7%, respectively. This improvement was corroborated through the measurement of the residual elastic modulus. Finally, the laminates presented an accumulation of inelastic deformation (ratcheting), whereas this phenomena was studied for two frequencies, 0.2Hz and 2 Hz.
DOI: 10.6084/m9.figshare.14321758
title: Analysis of the 3-Glycidoxypropyltrimethoxysilane (GPTMS) hydrolysis by infrared spectroscopy

description: ABSTRACT The study of silanes and polymers with special functions is increasing and the development of materials from silane-based polymers follows this trend. In this way, the hydrolysis of 3-Glycidoxypropyltrimethoxysilane (GPTMS) was studied as a function of the hydrolysis time in solutions with 50% of alcoholic solvents by infrared spectroscopy. It was verified that it was possible to analyze qualitatively and quantitatively the chemical reactions involving the hydrolysis / condensation of GPTMS and the main kinetics variations during the process. The results suggest that up to 30 minutes of hydrolysis, the predominant reactions are hydrolysis of the alkoxy groups, with the generation of the Si-OH groups and alcohol, in this case methanol. From 30 minutes, there is a large amount of silanols in the solution that tend to condense and form siloxane groups, which has this reaction accelerated from 60 minutes. Already, from 70-80 minutes, the reactions tend to decrease the kinetics, due to the absence of silanols and the hydrolysis / condensation process.
DOI: 10.6084/m9.figshare.14321758.v1
title: Analysis of the 3-Glycidoxypropyltrimethoxysilane (GPTMS) hydrolysis by infrared spectroscopy

description: ABSTRACT The study of silanes and polymers with special functions is increasing and the development of materials from silane-based polymers follows this trend. In this way, the hydrolysis of 3-Glycidoxypropyltrimethoxysilane (GPTMS) was studied as a function of the hydrolysis time in solutions with 50% of alcoholic solvents by infrared spectroscopy. It was verified that it was possible to analyze qualitatively and quantitatively the chemical reactions involving the hydrolysis / condensation of GPTMS and the main kinetics variations during the process. The results suggest that up to 30 minutes of hydrolysis, the predominant reactions are hydrolysis of the alkoxy groups, with the generation of the Si-OH groups and alcohol, in this case methanol. From 30 minutes, there is a large amount of silanols in the solution that tend to condense and form siloxane groups, which has this reaction accelerated from 60 minutes. Already, from 70-80 minutes, the reactions tend to decrease the kinetics, due to the absence of silanols and the hydrolysis / condensation process.
DOI: 10.6084/m9.figshare.14321760.v1
title: Waterproofing of bottle gourd (Lagenaria siceraria) with castor oil polyurethane resin

description: ABSTRACT Castor oil is widely used in chemical industry as raw material for paints, coatings, lubricants and a wide variety of other products. It is an important alternative to petrochemical feedstocks for the synthesis of polyurethanes (PU), besides being cost competitive and environmentally friendly alternative. It is used as a substitute for formaldehyde adhesives to produce composites and particleboards. Higher percentages of the resin tend to cause low water absorption and dimensional changes in the panels, so it has potential to use as waterproofing of natural materials. Bottle gourd is a fruit, used worldwide by different peoples as a raw material for the production of artifacts since many thousands of years. After the drying period, the inner part of the shell acquires characteristics similar to wood and the outer shell becomes impermeable. The objective of the work is increasing the durability and extend the useful life of the bottle gourd for use in the product design by waterproofing the material with polyurethane resin derived from castor oil. Untreated samples were compared with one and two layer resin samples. For the water absorption test, reference was made to standard NBR 15316: Medium density fiberboard. The analysis of the results was made through Scanning Electron Microscopy (SEM), water absorption test and contact angle. As a result, the application of the PU resin of castor oil reduced the water absorption indexes, and the samples with two layers of resin obtained the best results.
DOI: 10.6084/m9.figshare.14321760
title: Waterproofing of bottle gourd (Lagenaria siceraria) with castor oil polyurethane resin

description: ABSTRACT Castor oil is widely used in chemical industry as raw material for paints, coatings, lubricants and a wide variety of other products. It is an important alternative to petrochemical feedstocks for the synthesis of polyurethanes (PU), besides being cost competitive and environmentally friendly alternative. It is used as a substitute for formaldehyde adhesives to produce composites and particleboards. Higher percentages of the resin tend to cause low water absorption and dimensional changes in the panels, so it has potential to use as waterproofing of natural materials. Bottle gourd is a fruit, used worldwide by different peoples as a raw material for the production of artifacts since many thousands of years. After the drying period, the inner part of the shell acquires characteristics similar to wood and the outer shell becomes impermeable. The objective of the work is increasing the durability and extend the useful life of the bottle gourd for use in the product design by waterproofing the material with polyurethane resin derived from castor oil. Untreated samples were compared with one and two layer resin samples. For the water absorption test, reference was made to standard NBR 15316: Medium density fiberboard. The analysis of the results was made through Scanning Electron Microscopy (SEM), water absorption test and contact angle. As a result, the application of the PU resin of castor oil reduced the water absorption indexes, and the samples with two layers of resin obtained the best results.
DOI: 10.6084/m9.figshare.14321761.v1
title: Characterization of the raw material with nanometric particle size used in the processing of the composite WC-10% Co

description: ABSTRACT The composite WC-10% Co is one of the materials most produced by the hardmetal fabrication industry. However, a better understanding of the effect of process parameters on their structural characteristics is sought, especially with respect to the formation of metastable phases - η. In this work, we used the Rietveld Method with X - Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Brunauer - Emmett - Teller (BET) to investigate the structure of the raw materials used in the production of hardmetal. The particle sizes as well as the identified morphologies for the WC and Co powders are reflections of their manufacturing process, which introduce residual stresses for WC powder, low crystallinity and a significant amorphous portion for Co powder. These characteristics were identified with XRD in comparison to the obtained diffraction pattern and crystallographic databases. After the powder mixing process, the phases were quantified and the effects of this process were identified on the unit cells of each phase. This work shows that the characterization route using the Rietveld Method is efficient to analyze the structure of these materials during their processing. It was observed that the mixing process using high energy milling equipment promotes a change in the density of WC unit cells by “pushing” Co atoms into their structure. This may accelerate the dissolution process of most WC particles during sintering. And contribute to the accentuated formation of metastable phases eta – η, damaging the balance between the mechanical properties of hardness and fracture toughness making the tool or piece very hard and not very tenacious.
DOI: 10.6084/m9.figshare.14321761
title: Characterization of the raw material with nanometric particle size used in the processing of the composite WC-10% Co

description: ABSTRACT The composite WC-10% Co is one of the materials most produced by the hardmetal fabrication industry. However, a better understanding of the effect of process parameters on their structural characteristics is sought, especially with respect to the formation of metastable phases - η. In this work, we used the Rietveld Method with X - Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Brunauer - Emmett - Teller (BET) to investigate the structure of the raw materials used in the production of hardmetal. The particle sizes as well as the identified morphologies for the WC and Co powders are reflections of their manufacturing process, which introduce residual stresses for WC powder, low crystallinity and a significant amorphous portion for Co powder. These characteristics were identified with XRD in comparison to the obtained diffraction pattern and crystallographic databases. After the powder mixing process, the phases were quantified and the effects of this process were identified on the unit cells of each phase. This work shows that the characterization route using the Rietveld Method is efficient to analyze the structure of these materials during their processing. It was observed that the mixing process using high energy milling equipment promotes a change in the density of WC unit cells by “pushing” Co atoms into their structure. This may accelerate the dissolution process of most WC particles during sintering. And contribute to the accentuated formation of metastable phases eta – η, damaging the balance between the mechanical properties of hardness and fracture toughness making the tool or piece very hard and not very tenacious.
DOI: 10.6084/m9.figshare.14321763.v1
title: Mathematical model of a combustion chamber of a pirotubular boiler using the matlab-simulink tool

description: ABSTRACT This article presents the implementation of the mathematical model of the combustion chamber of a pyro-tubular boiler, by means of the approach of mass, energy and stoichiometric balances. These balances were described by the input components (air and fuel) that are presented in the combustion zone, based on the concept of maintaining the stoichiometric relationship between them, which were simulated through the computational tools such as the ESS and Matlab®, in order to determine the behavior of combustion gases depending on the type of chemical reaction presented. Likewise, it was determined the amount of carbons and hydrogens that make up the study fuels (ACMP and kerosene), as well as the kmol / s that compose the air, with the objective of analyzing its oxidation and determining the production of [CO]_(2,) H_2 O. Finally, the respective comparison was made analyzing the values of pressure and temperature in the three types of combustion, stoichiometric, with presence of unburned and with excess air. The approach of the mathematical model was applied for the two types of study fuels.