cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14321908.v1
title: Bidimensional matrix of cellulose obtained from vegetable leaf aiming bone repair: morphological and chemical characterization

description: ABSTRACT Maxillofacial orthopedic surgery have as one of its biggest challenges the effective bone repair, especially in cases of extensive loss of bone tissue due to several causes. Currently, the high demand for organ and tissue transplants and grafts has driven the search for materials capable of acting in the tissue repair process. Through contact with the interface of biological systems, biomaterials aim to evaluate, treat, augment or replace a body tissue, organ or function. Therefore, based on the architecture, biocompatibility of the cellulose extracellular matrix, as well as the presence of vascular system in the structure of spinach leaves, it is proposed to investigate a chemical treatment aiming at its use as a support for periosteal human tissue growth. In this context, cellulose appears as an option due to its characteristics of biodegradability, biocompatibility, low cost and for being a sustainable alternative. Different forms of isolated cellulose and its derivatives, as well as associated with other biomaterials, have been increasingly researched for use as a matrix in tissue repair processes. Considering the characteristics of cellulose as biomaterial, this study aims to characterize a plant leaf in the native form and after chemical process using ionic and nonionic solutions, establishing comparative analysis of the changes caused by processing and its potential for use as a two-dimensional matrix in bone tissue repair. Detergent immersion and perfusion techniques were used as protocols, as well as exposure of some samples to glutaraldehyde, with the purpose of cross-linking the polymeric matrix, as well as immersion in simulated body fluid (SBF). The materials resulting from chemical processing were subjected to scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). At the end of the characterizations, it was concluded that the protocol used is a viable option for low cost cellulose processing, which produces acceptable structural changes in the final product, but assays as deoxyribonucleic acid (DNA) quantification and cytotoxicity tests are suggested.
DOI: 10.34740/kaggle/dsv/2060086
title: YouTube Trending Video Dataset (updated daily)
DOI: 10.6084/m9.figshare.14321911.v1
title: Study of Cold Patch Asphalt Concrete

description: ABSTRACT Asphalt mixtures are the main types of materials that make up the asphalt surface layers of Brazilian pavements. In this way, this study aimed to study asphalt mixtures, known as Stock Asphalt Concrete (CAE), which has as its differential the proposal to be stored in bulk or bagged and applied cold. The physical, volumetric and mechanical characterizations of three CAE samples from different manufacturers were performed to understand its composition and mechanical behavior. In addition, particle size evaluations were performed using Bailey and Dominant Aggregate Size Range (DASR) methodologies. The results showed that CAE mixtures did not meet the Brazilian standard requirements and presented different results than expected for a conventional asphalt concrete, indicating that it should not be approached as such. In addition, CAE did not meet the workability and volume parameters. The binder viscosity, dynamic modulus and Flow Number results indicated that one of the samples has high rigidity, which may be related to the aging of the asphalt binder and consequent stiffening of the mixture. Finally, it was found that CAE is aging during storage, which is not suitable for asphalt mixtures. Therefore, one concluded that CAE, without the adoption of production and application control criteria, cannot be used as a new surface course, and its application is limited only for maintenance works as blacktop.
DOI: 10.6084/m9.figshare.14321911
title: Study of Cold Patch Asphalt Concrete

description: ABSTRACT Asphalt mixtures are the main types of materials that make up the asphalt surface layers of Brazilian pavements. In this way, this study aimed to study asphalt mixtures, known as Stock Asphalt Concrete (CAE), which has as its differential the proposal to be stored in bulk or bagged and applied cold. The physical, volumetric and mechanical characterizations of three CAE samples from different manufacturers were performed to understand its composition and mechanical behavior. In addition, particle size evaluations were performed using Bailey and Dominant Aggregate Size Range (DASR) methodologies. The results showed that CAE mixtures did not meet the Brazilian standard requirements and presented different results than expected for a conventional asphalt concrete, indicating that it should not be approached as such. In addition, CAE did not meet the workability and volume parameters. The binder viscosity, dynamic modulus and Flow Number results indicated that one of the samples has high rigidity, which may be related to the aging of the asphalt binder and consequent stiffening of the mixture. Finally, it was found that CAE is aging during storage, which is not suitable for asphalt mixtures. Therefore, one concluded that CAE, without the adoption of production and application control criteria, cannot be used as a new surface course, and its application is limited only for maintenance works as blacktop.
DOI: 10.6084/m9.figshare.14321913
title: Rheological evaluation at varied temperatures of cementitious pastes containing different types of polycarboxylate superplasticizers admixtures

description: ABSTRACT The study of the rheological parameters of the cementitious pastes can provide important information on the performance of fresh concretes in which they will be applied. In this context, this paper aims to study the effects of temperature on the rheological parameters of cementitious pastes added with superplasticizers. It is approached the analysis of the effect of type of cement in pastes rheological behavior, as well as the study of the action of superplasticizers based on polycarboxylate considering its function and its contents in the mixture. The pastes were evaluated by the mini-slump test and the parameters of yield stress, plastic viscosity and thixotropy were estimated by the rotational rheometry test and application of Bingham and Herschel-Bulkley fluid models. The results indicated that the increase in temperature led to a reduction of the yield stresses, plastic viscosities and thixotropy of pastes. A similar effect occurred after increasing the admixture content up to the saturation content. For formulations with the binder of highest content of pozzolan, the yield stress and plastic viscosities were higher by up to 80 and 70%, respectively. The rheological data indicate that admixtures of different functions (spreading, maintenance and multifunctional), although having the same base, influence in a different way the rheological parameters and plasticity of cementitious pastes.
DOI: 10.6084/m9.figshare.14321913.v1
title: Rheological evaluation at varied temperatures of cementitious pastes containing different types of polycarboxylate superplasticizers admixtures

description: ABSTRACT The study of the rheological parameters of the cementitious pastes can provide important information on the performance of fresh concretes in which they will be applied. In this context, this paper aims to study the effects of temperature on the rheological parameters of cementitious pastes added with superplasticizers. It is approached the analysis of the effect of type of cement in pastes rheological behavior, as well as the study of the action of superplasticizers based on polycarboxylate considering its function and its contents in the mixture. The pastes were evaluated by the mini-slump test and the parameters of yield stress, plastic viscosity and thixotropy were estimated by the rotational rheometry test and application of Bingham and Herschel-Bulkley fluid models. The results indicated that the increase in temperature led to a reduction of the yield stresses, plastic viscosities and thixotropy of pastes. A similar effect occurred after increasing the admixture content up to the saturation content. For formulations with the binder of highest content of pozzolan, the yield stress and plastic viscosities were higher by up to 80 and 70%, respectively. The rheological data indicate that admixtures of different functions (spreading, maintenance and multifunctional), although having the same base, influence in a different way the rheological parameters and plasticity of cementitious pastes.
DOI: 10.6084/m9.figshare.14321916
title: Segregation of Mn into GaAsMn thin films prepared by magnetron sputtering

description: ABSTRACT Currently, the manufacture of thin films of GaAs doped with Mn (GaAsMn) on Si (100), is an object of great interest, due to its possible integration with silicon technology, generating a significant development in the functionality of the devices optoelectronics and spintronics. In this work, we present a systematic study of the structural, optical, morphological and magnetic characterization of GaAsMn thin films prepared by R.F sputtering on a Si (100) substrate, for growth temperatures of 100 and 200 oC, respectively. From Raman spectra, the transverse optical (TO) and longitudinal optical (LO) vibrational modes, located at 290 cm-1 and 265 cm-1 of GaAs were identified. Additionally, vibrational modes of MnAs were identified, due to the replacement of Ga atoms with Mn atoms in high concentrations. The segregation of Mn was bear out by X-ray diffraction, where crystalline planes are evidenced in the directions (400) and (200) of polycrystalline GaAs, and crystallographic planes belonging to the Mn1+xAs phases. The morphology and growth mode of the thin films of GaAsMn / Si (100), was carried out by means of atomic force microscopy (AFM) and scanning electron microscopy (SEM) images, taken on the surface and in cross-section, respectively. Finally, an analysis of the magnetic properties of the GaAs thin films made from magnetic force microscopy (MFM) images, evidence surface magnetic domains formation, which depending on growth conditions. We concluded that, all properties of GaAsMn thin films are depending on growth conditions.
DOI: 10.6084/m9.figshare.14321916.v1
title: Segregation of Mn into GaAsMn thin films prepared by magnetron sputtering

description: ABSTRACT Currently, the manufacture of thin films of GaAs doped with Mn (GaAsMn) on Si (100), is an object of great interest, due to its possible integration with silicon technology, generating a significant development in the functionality of the devices optoelectronics and spintronics. In this work, we present a systematic study of the structural, optical, morphological and magnetic characterization of GaAsMn thin films prepared by R.F sputtering on a Si (100) substrate, for growth temperatures of 100 and 200 oC, respectively. From Raman spectra, the transverse optical (TO) and longitudinal optical (LO) vibrational modes, located at 290 cm-1 and 265 cm-1 of GaAs were identified. Additionally, vibrational modes of MnAs were identified, due to the replacement of Ga atoms with Mn atoms in high concentrations. The segregation of Mn was bear out by X-ray diffraction, where crystalline planes are evidenced in the directions (400) and (200) of polycrystalline GaAs, and crystallographic planes belonging to the Mn1+xAs phases. The morphology and growth mode of the thin films of GaAsMn / Si (100), was carried out by means of atomic force microscopy (AFM) and scanning electron microscopy (SEM) images, taken on the surface and in cross-section, respectively. Finally, an analysis of the magnetic properties of the GaAs thin films made from magnetic force microscopy (MFM) images, evidence surface magnetic domains formation, which depending on growth conditions. We concluded that, all properties of GaAsMn thin films are depending on growth conditions.
DOI: 10.6084/m9.figshare.14321914.v1
title: Evaluation of nano-TiO2 on properties of cementitious mortars

description: ABSTRACT This work deals with the effect in fresh and hardened properties of nano-TiO2 as addition in cement-based mortars. Three commercial nano-TiO2 powders were characterized by laser granulometry, XRD, FRX, zeta potential, BET and SEM. Two cementitious mortars were produced with nano-TiO2, an industrialized and a non-industrialized type; then, these mortars were characterized by flowability, surface roughness, flexural strength and surface fracture. The results showed that the nano-TiO2 addition reduced the flowability in terms of spread on table of the mortars. For surface roughness, in the industrialized mortars, the nanoparticles resulted in a smoother surface, while in the non-industrialized mortars, the nanoparticles formed a rougher surface. For flexural strength, in the non-industrialized mortars, the higher the nanoparticles amount, the higher the strength, while in the industrialized mortars no tendency was verified. In addition, from SEM analysis, it was noted that the fracture of the samples presented a tortuous aspect and growth through the region between cement paste and aggregates.
DOI: 10.6084/m9.figshare.14321914
title: Evaluation of nano-TiO2 on properties of cementitious mortars

description: ABSTRACT This work deals with the effect in fresh and hardened properties of nano-TiO2 as addition in cement-based mortars. Three commercial nano-TiO2 powders were characterized by laser granulometry, XRD, FRX, zeta potential, BET and SEM. Two cementitious mortars were produced with nano-TiO2, an industrialized and a non-industrialized type; then, these mortars were characterized by flowability, surface roughness, flexural strength and surface fracture. The results showed that the nano-TiO2 addition reduced the flowability in terms of spread on table of the mortars. For surface roughness, in the industrialized mortars, the nanoparticles resulted in a smoother surface, while in the non-industrialized mortars, the nanoparticles formed a rougher surface. For flexural strength, in the non-industrialized mortars, the higher the nanoparticles amount, the higher the strength, while in the industrialized mortars no tendency was verified. In addition, from SEM analysis, it was noted that the fracture of the samples presented a tortuous aspect and growth through the region between cement paste and aggregates.
DOI: 10.6084/m9.figshare.14321937
title: Evaluation of the effect of fatigue on the modulus of elasticity in static bending of plywood panels

description: ABSTRACT The panels have been increasingly used in civil and rural buildings, among others, especially those plywood panels by good mechanical performance. In many applications, panels may be subject to cyclic loading, and thus, the knowledge of the effect of fatigue is of fundamental importance. However, the standards ABNT NBR ISO 2426 [12], NBR ISO 1096 [13], NBR 9489 [14] and NBR 9533 [15] which have the classifications and test methods for panels, do not consider the effect of fatigue in material properties, which motivates the development of researches in this area. The objective of this work was to evaluate the effect of the number cyclic fatigue load (NC) (0 - reference, 3600, 7200, 22500, 45000, 67500, 90000) for the oscillation frequency equal to 1.0 Hz in the bending modulus of elasticity (MOE) of commercial eucalyptus plywood panels. Six specimens were fabricated for each number of cycles, resulting in 36 samples. The results evidenced significant reductions of the MOE from 22500 cycles, implying that 0, 3600 and 7200 cycles provided statistically equivalent results. The logarithmic regression model was the most representative (R² = 64.28%), presenting as an alternative in the prediction of the MOE decay for fatigue cycles higher than those evaluated in this study.
DOI: 10.6084/m9.figshare.14321937.v1
title: Evaluation of the effect of fatigue on the modulus of elasticity in static bending of plywood panels

description: ABSTRACT The panels have been increasingly used in civil and rural buildings, among others, especially those plywood panels by good mechanical performance. In many applications, panels may be subject to cyclic loading, and thus, the knowledge of the effect of fatigue is of fundamental importance. However, the standards ABNT NBR ISO 2426 [12], NBR ISO 1096 [13], NBR 9489 [14] and NBR 9533 [15] which have the classifications and test methods for panels, do not consider the effect of fatigue in material properties, which motivates the development of researches in this area. The objective of this work was to evaluate the effect of the number cyclic fatigue load (NC) (0 - reference, 3600, 7200, 22500, 45000, 67500, 90000) for the oscillation frequency equal to 1.0 Hz in the bending modulus of elasticity (MOE) of commercial eucalyptus plywood panels. Six specimens were fabricated for each number of cycles, resulting in 36 samples. The results evidenced significant reductions of the MOE from 22500 cycles, implying that 0, 3600 and 7200 cycles provided statistically equivalent results. The logarithmic regression model was the most representative (R² = 64.28%), presenting as an alternative in the prediction of the MOE decay for fatigue cycles higher than those evaluated in this study.
DOI: 10.6084/m9.figshare.14321938
title: Methylene blue adsorption in hydrocarbons textile waste

description: ABSTRACT Textile products, increasingly present in our daily lives, generate a large amount of waste, whether solid or liquid. Giving the right destination or even transforming solid waste is the new challenge to be faced. Solid waste, usually tissue scraps, contains a large amount of organic compounds that can be carbonized. In this context, the main objective of the present study was the synthesis of hydrochars using textile waste. The hydrochars formed may be used as dye adsorbents such as methylene blue. Hydrochars synthesis used a residue/water ratio of 3/80 mass (g)/volume (mL) at a temperature of 220 °C. The time was investigated between 6 to 12 hours, and in the latter there was 71.2% carbon, obtained by EDS, and followed for characterization by ATR-FTIR, XDR, SEM and pHzpc. The proposed material presented significant adsorption capacity in alkaline environment, around 72 mg.g-1. The kinetic data obtained were better adjusted in the pseudo second-order model suggesting that the adsorption process was controlled by chemissorption, with electron sharing or exchange between adsorbent and adsorbate. Langmuir model presented better correlation with equilibrium data. Hydrochars synthesized with textile waste therefore have great potential in applications, aiming at the removal of organic pollutants from liquid solutions.
DOI: 10.6084/m9.figshare.14321938.v1
title: Methylene blue adsorption in hydrocarbons textile waste

description: ABSTRACT Textile products, increasingly present in our daily lives, generate a large amount of waste, whether solid or liquid. Giving the right destination or even transforming solid waste is the new challenge to be faced. Solid waste, usually tissue scraps, contains a large amount of organic compounds that can be carbonized. In this context, the main objective of the present study was the synthesis of hydrochars using textile waste. The hydrochars formed may be used as dye adsorbents such as methylene blue. Hydrochars synthesis used a residue/water ratio of 3/80 mass (g)/volume (mL) at a temperature of 220 °C. The time was investigated between 6 to 12 hours, and in the latter there was 71.2% carbon, obtained by EDS, and followed for characterization by ATR-FTIR, XDR, SEM and pHzpc. The proposed material presented significant adsorption capacity in alkaline environment, around 72 mg.g-1. The kinetic data obtained were better adjusted in the pseudo second-order model suggesting that the adsorption process was controlled by chemissorption, with electron sharing or exchange between adsorbent and adsorbate. Langmuir model presented better correlation with equilibrium data. Hydrochars synthesized with textile waste therefore have great potential in applications, aiming at the removal of organic pollutants from liquid solutions.
DOI: 10.6084/m9.figshare.14321939
title: Pozzolanic effect investigation of silica hydrosol (SH) nanoparticles with different granulometric distributions dispersed in cement paste

description: ABSTRACT The addition of nanomaterials to concrete allows structural modifications, improving their properties like mechanical strength and durability. Within these possible nanoscale materials is silica hydrosol (SH). There are many studies highlighting the influence of the surface area of SH particles on the pozzolanic reaction with cement, however little has been studied on the influence of percentage and particle size on the reaction. In this context, the objective of this work was to investigate the influence of the particle size distribution of silica nanoparticles on the pozzolanic reaction in cement pastes, from the comparison of 4 colloidal suspensions. The addition content of these particles, with different sizes, was defined as 3.00% (SH-A), 0.89% (SH-B), 0.77% (SH-C) and 0.32% (SH-D), to equalize the surface areas of all of them, so that the only variables were the percentage and particle size distribution of the silicas. The pozzolanic effect was evaluated by the direct method named Modified Chapelle test, and by indirect methods like Fourier transform infrared spectroscopy (FT IR), and mechanical strength tests. It was concluded that for the same surface area resulting from the addition of SH, the sample that presented the best performance was the CP SH-A, which presented the largest particle size and volume of addition. However, when analysing the relative performance, regarding the concentration of SH added to the paste, the CP SH-D sample obtained the highest mechanical resistance and the highest pozzolanic index. It showed that concentration and particle size, not just surface area, influenced the performance of the nanosilica pozzolanic reaction. The conclusions obtained in the present work allow a better understanding about the addition of SH in cementitious composites and how the content and particle size of such products impact their performance.