cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14321896
title: Superficial treatment by anodization in order to obtain titanium oxide nanotubes applicable in implantology

description: ABSTRACT Titanium and its alloys are the most popular metals applied on end osseous implants manufacturing. Commercially pure titanium (Ti c.p.) has been successfully used as a biomaterial because of its mechanical and chemical properties, excellent corrosion resistance and biocompatibility. In order to improve and accelerate the osseointegration process after implantation, superficial treatments are performed aiming properties that stimulate the growth of the newly-formed bone. In this work, self organized titanium dioxide (TiO2) nanotubes were obtained by anodic oxidation on Ti c.p. (grade 2). Also, it has been shown that the process is industrially reproducible for this purpose. As parameters for the anodizing process, it was concluded that the optimal electrolyte was H3PO4 solution + 0.15% HF under potentiostatic mode for 30 minutes. Potentials of 1, 5, 10, 15 and 20 V were tested in order to verify the best conditions to obtain nanotubes. In this case, potential was set at 10V. The morphology of the samples was characterized by Scanning Electron Microscopy (SEM), Scanning Electron Microscopy with Field Emission (SEM-FEG) and Atomic Force Microscopy (AFM). The results showed the nanotubes formation throughout the titanium samples surface. In accordance to the obtained roughness, it was observed that the formed nanotubes film is thin, however, the literature indicates that the film thickness is not relevant on the performance of nanostructures as optimizers of the osseointegration process, unlike the nanotubes morphology and diameter. In the wettability analysis, the nanotubes behaved as hydrophilic. Therefore, it is possible to obtain TiO2 nanotubes for using in implants by a superficial treatment, allowing a better osseointegration quality.
DOI: 10.6084/m9.figshare.14321896.v1
title: Superficial treatment by anodization in order to obtain titanium oxide nanotubes applicable in implantology

description: ABSTRACT Titanium and its alloys are the most popular metals applied on end osseous implants manufacturing. Commercially pure titanium (Ti c.p.) has been successfully used as a biomaterial because of its mechanical and chemical properties, excellent corrosion resistance and biocompatibility. In order to improve and accelerate the osseointegration process after implantation, superficial treatments are performed aiming properties that stimulate the growth of the newly-formed bone. In this work, self organized titanium dioxide (TiO2) nanotubes were obtained by anodic oxidation on Ti c.p. (grade 2). Also, it has been shown that the process is industrially reproducible for this purpose. As parameters for the anodizing process, it was concluded that the optimal electrolyte was H3PO4 solution + 0.15% HF under potentiostatic mode for 30 minutes. Potentials of 1, 5, 10, 15 and 20 V were tested in order to verify the best conditions to obtain nanotubes. In this case, potential was set at 10V. The morphology of the samples was characterized by Scanning Electron Microscopy (SEM), Scanning Electron Microscopy with Field Emission (SEM-FEG) and Atomic Force Microscopy (AFM). The results showed the nanotubes formation throughout the titanium samples surface. In accordance to the obtained roughness, it was observed that the formed nanotubes film is thin, however, the literature indicates that the film thickness is not relevant on the performance of nanostructures as optimizers of the osseointegration process, unlike the nanotubes morphology and diameter. In the wettability analysis, the nanotubes behaved as hydrophilic. Therefore, it is possible to obtain TiO2 nanotubes for using in implants by a superficial treatment, allowing a better osseointegration quality.
DOI: 10.6084/m9.figshare.14321898.v1
title: Influence of heat treatment medium on properties of the bovine hydroxyapatite/magnetite systems

description: ABSTRACT Technological processes for the synthesis of composite systems based on bovine (rather than synthetic) hydroxyapatite are rarely described. That’s why the influence of the heat treatment medium on the properties of the composite system bovine hydroxyapatite/magnetite (BHA/Fe3O4) obtained using physico-mechanical and chemical methods were investigated. It was established that the most efficient medium for heat treatment of studied materials is vacuum. Due to XRD analysis data allow us to assert that the most perfect lattice is formed with the use of the chemical method for production and heat treatment in a vacuum (crystallinity 86%), and the least perfect one is formed by the mechanical method for production and heat treatment in a nitrogen medium (71%). The method for adding magnetite has only a minor effect. Investigated conditions of heat treatment of composite systems BHA/Fe3O4 promoted obtaining optimal magnetic properties and stable behavior in experiments in vitro.
DOI: 10.6084/m9.figshare.14321898
title: Influence of heat treatment medium on properties of the bovine hydroxyapatite/magnetite systems

description: ABSTRACT Technological processes for the synthesis of composite systems based on bovine (rather than synthetic) hydroxyapatite are rarely described. That’s why the influence of the heat treatment medium on the properties of the composite system bovine hydroxyapatite/magnetite (BHA/Fe3O4) obtained using physico-mechanical and chemical methods were investigated. It was established that the most efficient medium for heat treatment of studied materials is vacuum. Due to XRD analysis data allow us to assert that the most perfect lattice is formed with the use of the chemical method for production and heat treatment in a vacuum (crystallinity 86%), and the least perfect one is formed by the mechanical method for production and heat treatment in a nitrogen medium (71%). The method for adding magnetite has only a minor effect. Investigated conditions of heat treatment of composite systems BHA/Fe3O4 promoted obtaining optimal magnetic properties and stable behavior in experiments in vitro.
DOI: 10.6084/m9.figshare.14321899
title: Pigmented zircônia-yttria obtained by Pechini Method for dental applications

description: ABSTRACT The introduction of zirconia (ZrO2) as a dental material, represents a major advance when compared to other materials traditionally used for this purpose. This material stands out due to its excellent properties such as mechanical resistance and biocompatibility. However, there are limitations regarding its white color and high opacity, and it is not possible to mimic the characteristics of human dentition, thus affecting the aesthetic concept of these materials and reducing patient comfort. This work proposes to develop pigmented zirconia powders using the Pechini method, doping them with iron oxide in different concentrations (3 %, 2 %, 1 %, 0.5 %, 0.25 mol%) and itria, later calcine them at a temperature of 1000 °C in order to obtain the most effective chemical mixture, close to the shade of human dentin. The samples were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), toxicity testing and colorimetric evaluation, confirming the presence of iron within the zirconia microstructure and its modifications caused in the material. The obtained results indicate that the crystallite sizes of the synthesized powders increased from 35,45 nm to 48,97 nm when the iron concentration increased from 0 % to 3 mol%. The EDS spectra indicated the presence of iron in all the samples, with varying concentrations of the pigmentant agent. The method used was effective for the production of zirconia powders with varied color nuances, having great potential for dental applications.
DOI: 10.6084/m9.figshare.14321899.v1
title: Pigmented zircônia-yttria obtained by Pechini Method for dental applications

description: ABSTRACT The introduction of zirconia (ZrO2) as a dental material, represents a major advance when compared to other materials traditionally used for this purpose. This material stands out due to its excellent properties such as mechanical resistance and biocompatibility. However, there are limitations regarding its white color and high opacity, and it is not possible to mimic the characteristics of human dentition, thus affecting the aesthetic concept of these materials and reducing patient comfort. This work proposes to develop pigmented zirconia powders using the Pechini method, doping them with iron oxide in different concentrations (3 %, 2 %, 1 %, 0.5 %, 0.25 mol%) and itria, later calcine them at a temperature of 1000 °C in order to obtain the most effective chemical mixture, close to the shade of human dentin. The samples were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), toxicity testing and colorimetric evaluation, confirming the presence of iron within the zirconia microstructure and its modifications caused in the material. The obtained results indicate that the crystallite sizes of the synthesized powders increased from 35,45 nm to 48,97 nm when the iron concentration increased from 0 % to 3 mol%. The EDS spectra indicated the presence of iron in all the samples, with varying concentrations of the pigmentant agent. The method used was effective for the production of zirconia powders with varied color nuances, having great potential for dental applications.
DOI: 10.6084/m9.figshare.14321901
title: Physical stabilization of a sandy lateritic soil using ceramic wastes

description: ABSTRACT The growth of the cities has brought with environmental, social and economic problems, doing an awareness of sustainable development essential for the survival of humanity and for the preservation of the environment. In this way, it is important to highlight the amount of waste from construction and waste from the red ceramic industry and the significant growth of both in the last years. An alternative to this waste is its use in layers of pavements. The aim of this paper is to assess the possibility of use red ceramic wastes in the stabilization of a sandy lateritic soil. For that, three different percentages of ceramic wastes (0, 50 and 60%, in mass) were assessed and the influence of compaction energy was verified by California Bearing ratio (CBR) test. The obtained results showed that the use of ceramic wastes is a viable practice in the soil stabilization and, the enhancement on the energy compaction can improve significantly the CBR, yielding increment of 50% for samples containing 60% of ceramic waste.
DOI: 10.6084/m9.figshare.14321901.v1
title: Physical stabilization of a sandy lateritic soil using ceramic wastes

description: ABSTRACT The growth of the cities has brought with environmental, social and economic problems, doing an awareness of sustainable development essential for the survival of humanity and for the preservation of the environment. In this way, it is important to highlight the amount of waste from construction and waste from the red ceramic industry and the significant growth of both in the last years. An alternative to this waste is its use in layers of pavements. The aim of this paper is to assess the possibility of use red ceramic wastes in the stabilization of a sandy lateritic soil. For that, three different percentages of ceramic wastes (0, 50 and 60%, in mass) were assessed and the influence of compaction energy was verified by California Bearing ratio (CBR) test. The obtained results showed that the use of ceramic wastes is a viable practice in the soil stabilization and, the enhancement on the energy compaction can improve significantly the CBR, yielding increment of 50% for samples containing 60% of ceramic waste.
DOI: 10.6084/m9.figshare.14321904
title: Influence of silicon, strontium and aluminum oxides on silicon nitride ceramics for bone replacements

description: ABSTRACT Although silicon nitride ceramics have been shown very propitious to be used for bone replacements, some characteristics can be controlled to improve their osseointegrations process. One of them is the intergranular phase whose composition can be specified to stimulate mineralization and osteoblastic production. In this paper, the intergranular glassy phase was projected in order to contain silicon, strontium and aluminum oxides. Silicon nitride samples containing different contents of SiO2, SrO and Al2O3 were sintered at 1815oC for 1 hour and characterized by scanning electron microscopy and X-ray diffraction. Hardness and fracture toughness were determined by Vickers hardness test and compressive strength was evaluated using an universal material testing machine. The biological behavior was studied in regard to cytotoxicity and cell proliferation by means of in vitro experiments. The samples reached high densities (higher than 95 %TD), total α→β-Si3N4 transformation, fracture toughness higher than 6.5 MPa.m1/2, compressive strength up to 2500 MPa and Vickers hardness less than 9.8 GPa. All samples were non-cytotoxic and able to promote cell proliferation with great potential to be used as components for bone replacements. However, that sample with high content of strontium had the best results of cell proliferation, proving the importance of a careful choice of intergranular phase composition in silicon nitride ceramics.
DOI: 10.6084/m9.figshare.14321904.v1
title: Influence of silicon, strontium and aluminum oxides on silicon nitride ceramics for bone replacements

description: ABSTRACT Although silicon nitride ceramics have been shown very propitious to be used for bone replacements, some characteristics can be controlled to improve their osseointegrations process. One of them is the intergranular phase whose composition can be specified to stimulate mineralization and osteoblastic production. In this paper, the intergranular glassy phase was projected in order to contain silicon, strontium and aluminum oxides. Silicon nitride samples containing different contents of SiO2, SrO and Al2O3 were sintered at 1815oC for 1 hour and characterized by scanning electron microscopy and X-ray diffraction. Hardness and fracture toughness were determined by Vickers hardness test and compressive strength was evaluated using an universal material testing machine. The biological behavior was studied in regard to cytotoxicity and cell proliferation by means of in vitro experiments. The samples reached high densities (higher than 95 %TD), total α→β-Si3N4 transformation, fracture toughness higher than 6.5 MPa.m1/2, compressive strength up to 2500 MPa and Vickers hardness less than 9.8 GPa. All samples were non-cytotoxic and able to promote cell proliferation with great potential to be used as components for bone replacements. However, that sample with high content of strontium had the best results of cell proliferation, proving the importance of a careful choice of intergranular phase composition in silicon nitride ceramics.
DOI: 10.6084/m9.figshare.14321905
title: Influence of aggregate degradation on the permeability of railway ballast

description: ABSTRACT The main function of the railway structure is to provide stability and security so that rail transport operates efficiently. Its main constituents on the subgrade are ballast, sub-ballast, sleepers and rails. The ballast is an element of the superstructure that is located between the sleepers and the sub-ballast. The main functions of the ballast are the stress distribution and the contribution to the drainage of the structure. However, the impact caused by the passage of the trains cause the degradation of the aggregate and produces fines that damages to the drainage of the structure. Ineffective drainage can lead to the appearance of defects in the superstructure such as the displacement of the sleepers and the unevenness of the railroad due to the occurrence of permanent deformations in the geotechnical layers. In this context, the objective of this work was to evaluate the degradation of the ballast and the way in which this phenomenon influences its draining capacity. For this, in a first step, characterization tests of the material were carried out. The experimental method consisted of the accelerated degradation of basalt samples in the abrasion Los Angeles drum. Then, the permeability evaluation of the material was performed. It was possible to verify the relation between the phenomena of fouling and permeability from the clean ballast to the highly fouled ballast. It was evidenced that the 19.1 mm aggregate fraction suffered greater degradation, contributing to the fines increase in the system, being responsible for the fouling phenomenon, representing a harmful element in relation to the drainage of the rail ballast.
DOI: 10.6084/m9.figshare.14321907
title: Influence the use of glass sludge on the thermal diffusivity of structural mor-tars using thermography

description: ABSTRACT Soda-lime-silica glass is a material with high recycling potential. However, its processing generates microparticles that are suspended in the water used for cooling the tools. This residue is inert and generally not reused. For disposal, the microparticles of glass are decanted using flocculants and the mud produced is deposited in landfills. According to the literature, these glass microparticles could act as supplementary cementitious material in Portland cement production. However, information on the thermal performance of these materials is scarce. This study investigates the thermal diffusivity of mortars for structural purposes made with Portland cement and pozzolanic soda-lime-silica glass mud. The mortars were produced with and without cement replacement for 10 and 20% natural mud and washed mud to remove the flocculant. The mortars were characterized for compressive strength and thermal diffusivity. The specific mass, the thermal conductivity and the heating profile of the mortars were also determined, requirements to evaluate the thermal diffusivity. The results indicate that glass mud with and without flocculant could be used in place of cement without compromising compressive strength due to its pozzolanic characteristics. In mortars with 10% mud without flocculant an increase of approximately 8% in compressive strength is observed. However, in all samples with glass mud, washed or not, there is a decrease of 3 to 4% in the specific mass and 17 to 18% in the thermal conductivity, indicating that the pozzolanic reaction did not occur to its full extent. Diffusivity, determined with the aid of infrared thermography, presents results compatible with the literature and indicates that the use of the residue does not significantly influence the thermal inertia of the mortars. Thus, glass mud in place of 10% and 20% Portland cement could be used in structural mortars without compromising the thermal performance of the system, in addition to contributing to the environment by providing adequate destination to the waste and reducing the withdrawal of raw materials for cement production.
DOI: 10.6084/m9.figshare.14321907.v1
title: Influence the use of glass sludge on the thermal diffusivity of structural mor-tars using thermography

description: ABSTRACT Soda-lime-silica glass is a material with high recycling potential. However, its processing generates microparticles that are suspended in the water used for cooling the tools. This residue is inert and generally not reused. For disposal, the microparticles of glass are decanted using flocculants and the mud produced is deposited in landfills. According to the literature, these glass microparticles could act as supplementary cementitious material in Portland cement production. However, information on the thermal performance of these materials is scarce. This study investigates the thermal diffusivity of mortars for structural purposes made with Portland cement and pozzolanic soda-lime-silica glass mud. The mortars were produced with and without cement replacement for 10 and 20% natural mud and washed mud to remove the flocculant. The mortars were characterized for compressive strength and thermal diffusivity. The specific mass, the thermal conductivity and the heating profile of the mortars were also determined, requirements to evaluate the thermal diffusivity. The results indicate that glass mud with and without flocculant could be used in place of cement without compromising compressive strength due to its pozzolanic characteristics. In mortars with 10% mud without flocculant an increase of approximately 8% in compressive strength is observed. However, in all samples with glass mud, washed or not, there is a decrease of 3 to 4% in the specific mass and 17 to 18% in the thermal conductivity, indicating that the pozzolanic reaction did not occur to its full extent. Diffusivity, determined with the aid of infrared thermography, presents results compatible with the literature and indicates that the use of the residue does not significantly influence the thermal inertia of the mortars. Thus, glass mud in place of 10% and 20% Portland cement could be used in structural mortars without compromising the thermal performance of the system, in addition to contributing to the environment by providing adequate destination to the waste and reducing the withdrawal of raw materials for cement production.
DOI: 10.6084/m9.figshare.14321908
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.