cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.5772450.v1
title: Use of expanded clay and silica fume in improvement of mechanical, physical and thermal performances of structural lightweight concretes

description: ABSTRACT The search for sustainable materials in civil construction, which presents a lower specific mass, better thermal performance and maintenance of mechanical resistance, represents a great challenge in the production and evaluation of structural lightweight concrete (SLC), which emerges as an alternative material to conventional concrete. In this study an investigation was carried out for the construction of concretes with high strength, low density and excellent thermal properties, in order to execute energy-efficient constructions. SLC were studied using two different granulometries of expanded clay (C05 and C15), where the coarse aggregate was replaced by C15 at 0, 25, 50, 75 and 100%. To promote the maintenance of consistency and resistance, superplasticizer (SPA) and silica fume (SF) were used in the mixtures. Based on the methodology used, the concretes were physically and mechanically characterized, in accordance with current national and international standards. The density of the concretes, in the hardened state, ranged from 1,787 to 2,400 kg/m³ and, for compressive strength, ranged from 26 to 53 MPa at 7 days of age. The thermal conductivity test, using the protected hot plate method, was performed according to EN 12667, where was observed a variation of 0.61 to 1.00 W/mK. Microstructural information of the interfacial transition zone (ITZ) between aggregate and cement matrix were obtained with the purpose of analyzing the relationship with mechanical resistance. The investigation revealed that, with the addition of expanded clay (C05 and C15) and SF in the concretes, there was reduction of the density and the mechanical resistance, while the thermal characteristics were improved.
DOI: 10.6084/m9.figshare.5772444
title: Shear strength of bamboo-bamboo connection: gluing pressure Influence

description: ABSTRACT The objective of this work is to determine the bonding pressure and the influence of the surface on the efficiency of the bamboo-bamboo bonding. The sizing pressure was defined as 7 treatments of zero, 2.5, 3.75, 5, 6.25, 7.50 and 8.75MPa. For this, test specimens composed of bamboo slides, Philostachys pubens, with bicomponent resorcinol formoldehyde adhesive were made. The mechanical characteristics of greatest influence on adhesive bonding are shear strength and slip modulus. These characteristics are influenced by the pressure and the bonding surface. In the determination of the influence of the bonding surface, specimens were prepared with three treatments: shell-core, shell-shell and core-core. The shear strength of the bamboo-bamboo bond showed better behavior at 2.5MPa pressure. The combination of sizing surface does not influence the bond strength; so any combination can be used.
DOI: 10.6084/m9.figshare.5772444.v1
title: Shear strength of bamboo-bamboo connection: gluing pressure Influence

description: ABSTRACT The objective of this work is to determine the bonding pressure and the influence of the surface on the efficiency of the bamboo-bamboo bonding. The sizing pressure was defined as 7 treatments of zero, 2.5, 3.75, 5, 6.25, 7.50 and 8.75MPa. For this, test specimens composed of bamboo slides, Philostachys pubens, with bicomponent resorcinol formoldehyde adhesive were made. The mechanical characteristics of greatest influence on adhesive bonding are shear strength and slip modulus. These characteristics are influenced by the pressure and the bonding surface. In the determination of the influence of the bonding surface, specimens were prepared with three treatments: shell-core, shell-shell and core-core. The shear strength of the bamboo-bamboo bond showed better behavior at 2.5MPa pressure. The combination of sizing surface does not influence the bond strength; so any combination can be used.
DOI: 10.6084/m9.figshare.5772438
title: Evaluation of the addition of glycerol to Cupriavidus necator culture medium over Poly(3-hydroxybutyrate) production

description: ABSTRACT Glycerol was used as a source of additional carbon in the production of Poly(3-hydroxybutyrate) (P(3HB)). The inverted sugar and glycerol concentrations and the temperature of the Cupriavidus necator culture medium were evaluated using a Central Composite Rotational Design (CCRD). The results showed that the increase in temperature and sugar concentration led to an increase in production and P(3HB) accumulation and when 15 g L-1 of glycerol was added better results were obtained, however these were not considered statistically significant. The best results were obtained at 38 °C and with 30 g L-1 of inverted sugar. Although not considered statistically significant, the addition of 15 g L-1 of glycerol increased the P(3HB) accumulation percentage by 15 %, thus in kinetic terms, greater productivity was obtained in 0.32 g L-1 h-1 polymer. Larger scale assays are being conducted to verify if the addition of glycerol improves the thermal and mechanical properties of the synthesized polymer.
DOI: 10.6084/m9.figshare.5772438.v1
title: Evaluation of the addition of glycerol to Cupriavidus necator culture medium over Poly(3-hydroxybutyrate) production

description: ABSTRACT Glycerol was used as a source of additional carbon in the production of Poly(3-hydroxybutyrate) (P(3HB)). The inverted sugar and glycerol concentrations and the temperature of the Cupriavidus necator culture medium were evaluated using a Central Composite Rotational Design (CCRD). The results showed that the increase in temperature and sugar concentration led to an increase in production and P(3HB) accumulation and when 15 g L-1 of glycerol was added better results were obtained, however these were not considered statistically significant. The best results were obtained at 38 °C and with 30 g L-1 of inverted sugar. Although not considered statistically significant, the addition of 15 g L-1 of glycerol increased the P(3HB) accumulation percentage by 15 %, thus in kinetic terms, greater productivity was obtained in 0.32 g L-1 h-1 polymer. Larger scale assays are being conducted to verify if the addition of glycerol improves the thermal and mechanical properties of the synthesized polymer.
DOI: 10.6084/m9.figshare.5772435
title: Common and uncommon features of focal splenic lesions on contrast-enhanced ultrasound: a pictorial review

description: Abstract The characterization of focal splenic lesions by ultrasound can be quite challenging. The recent introduction of contrast-enhanced ultrasound (CEUS) has come to play a valuable role in the field of imaging splenic pathologies, offering the possibility of an ionizing radiation-free investigation. Because CEUS has been incorporated into everyday clinical practice, malignant diseases such as focal lymphomatous infiltration, metastatic deposits, benign cysts, traumatic fractures, and hemangiomas can now be accurately depicted and characterized without the need for further imaging. More specifically, splenic traumatic fractures do not require additional imaging by computed tomography (with ionizing radiation exposure) for follow-up, because splenic fractures and their complications are safely imaged with CEUS. In the new era of CEUS, more patients benefit from radiation-free investigation of splenic pathologies with high diagnostic accuracy.
DOI: 10.6084/m9.figshare.5772435.v1
title: Common and uncommon features of focal splenic lesions on contrast-enhanced ultrasound: a pictorial review

description: Abstract The characterization of focal splenic lesions by ultrasound can be quite challenging. The recent introduction of contrast-enhanced ultrasound (CEUS) has come to play a valuable role in the field of imaging splenic pathologies, offering the possibility of an ionizing radiation-free investigation. Because CEUS has been incorporated into everyday clinical practice, malignant diseases such as focal lymphomatous infiltration, metastatic deposits, benign cysts, traumatic fractures, and hemangiomas can now be accurately depicted and characterized without the need for further imaging. More specifically, splenic traumatic fractures do not require additional imaging by computed tomography (with ionizing radiation exposure) for follow-up, because splenic fractures and their complications are safely imaged with CEUS. In the new era of CEUS, more patients benefit from radiation-free investigation of splenic pathologies with high diagnostic accuracy.
DOI: 10.6084/m9.figshare.5772432
title: Effect of co-doping with Ce, Tb and Mn on the morphological, structural and optical properties of alumina films

description: ABSTRACT The lighting system has undergone some changes over the years. Currently the LED (Light Emitting Diode) system has stood out, showing that it has the potential to emit light more efficiently and still reducing the consumption of electric energy. The main objective of this work was the analysis of the photoluminescence of the films produced using the spray-pyrolysis deposition technique, which has the characteristic of being a simple, low cost and efficient system. In addition, the effects of co-doping with cerium, terbium and manganese on the morphological, structural and optical properties of alumina films were investigated. The influence of the substrate temperature, which varied between 300 and 450 °C, on the absorbance, transmittance and photoluminescent emission spectra for films deposited by spray-pyrolysis on glass substrates was analyzed. The precursor solution flow was set at 0.5 mL/min and the deposition time of 3 minutes. By co-doping with Ce (5 at.%), Tb (1 at.%) and Mn (1 at.%) in alumina films was possible to obtain white light emission. The best luminescent emission condition was the sample deposited at 300 °C. The spray pyrolysis deposition technique proved effective in obtaining photoluminescent films, confirming the ability for applications in efficient lighting systems, such as w-LED (white light emitting diode).
DOI: 10.6084/m9.figshare.5772432.v1
title: Effect of co-doping with Ce, Tb and Mn on the morphological, structural and optical properties of alumina films

description: ABSTRACT The lighting system has undergone some changes over the years. Currently the LED (Light Emitting Diode) system has stood out, showing that it has the potential to emit light more efficiently and still reducing the consumption of electric energy. The main objective of this work was the analysis of the photoluminescence of the films produced using the spray-pyrolysis deposition technique, which has the characteristic of being a simple, low cost and efficient system. In addition, the effects of co-doping with cerium, terbium and manganese on the morphological, structural and optical properties of alumina films were investigated. The influence of the substrate temperature, which varied between 300 and 450 °C, on the absorbance, transmittance and photoluminescent emission spectra for films deposited by spray-pyrolysis on glass substrates was analyzed. The precursor solution flow was set at 0.5 mL/min and the deposition time of 3 minutes. By co-doping with Ce (5 at.%), Tb (1 at.%) and Mn (1 at.%) in alumina films was possible to obtain white light emission. The best luminescent emission condition was the sample deposited at 300 °C. The spray pyrolysis deposition technique proved effective in obtaining photoluminescent films, confirming the ability for applications in efficient lighting systems, such as w-LED (white light emitting diode).
DOI: 10.6084/m9.figshare.5772429
title: Zinc oxide nanoparticles synthesized by the polyol method:characterization and evaluation of the antibacterial activity

description: ABSTRACT The use of nanostructured materials synthesized from metal salts has increasingly attracted the attention of researchers and industries to develop innovative applications in areas such as energy, health and food. Due to the antibacterial properties of silver, copper and zinc oxide, they are potential substituents to the traditional antibacterial agents, such as organochlorines and arsenic derivatives. Once zinc oxide is not classified as heavy meta, has low toxicity, and is biocompatible, it appears as an alternative material for applications in the medical area and water treatment. The main objective of this work was to synthesize zinc oxide nanoparticles by the polyol method and evaluate the antibacterial activity of these nanostructures against the Gram negative bacteria Escherichia coli. The syntheses were carried out in the presence and absence of poly(vinyl pyrrolidone) to investigate the influence of this stabilizing agent on the morphological properties of the nanoparticles. All of the samples were characterized by UV-Vis spectrophotometry, X-ray diffractometry, field emission scanning electron microscopy and transmission electron microscopy. Tests to evaluate the antibacterial activity of different amounts of the zinc oxide nanoparticles were performed according to the ASTM E-2149. The results obtained demonstrated that the polyol method was able to produce zinc oxide nanoparticles with high purity and average diameter around 20 nm, regardless the presence of poly(vinyl pyrrolidone). Microbiological assays showed that zinc oxide nanoparticles produced excellent antibacterial activity against the bacteria Escherichia coli when applied at concentrations higher than 50 mg.L-1.
DOI: 10.6084/m9.figshare.5772429.v1
title: Zinc oxide nanoparticles synthesized by the polyol method:characterization and evaluation of the antibacterial activity

description: ABSTRACT The use of nanostructured materials synthesized from metal salts has increasingly attracted the attention of researchers and industries to develop innovative applications in areas such as energy, health and food. Due to the antibacterial properties of silver, copper and zinc oxide, they are potential substituents to the traditional antibacterial agents, such as organochlorines and arsenic derivatives. Once zinc oxide is not classified as heavy meta, has low toxicity, and is biocompatible, it appears as an alternative material for applications in the medical area and water treatment. The main objective of this work was to synthesize zinc oxide nanoparticles by the polyol method and evaluate the antibacterial activity of these nanostructures against the Gram negative bacteria Escherichia coli. The syntheses were carried out in the presence and absence of poly(vinyl pyrrolidone) to investigate the influence of this stabilizing agent on the morphological properties of the nanoparticles. All of the samples were characterized by UV-Vis spectrophotometry, X-ray diffractometry, field emission scanning electron microscopy and transmission electron microscopy. Tests to evaluate the antibacterial activity of different amounts of the zinc oxide nanoparticles were performed according to the ASTM E-2149. The results obtained demonstrated that the polyol method was able to produce zinc oxide nanoparticles with high purity and average diameter around 20 nm, regardless the presence of poly(vinyl pyrrolidone). Microbiological assays showed that zinc oxide nanoparticles produced excellent antibacterial activity against the bacteria Escherichia coli when applied at concentrations higher than 50 mg.L-1.
DOI: 10.6084/m9.figshare.5772423
title: A Small Quad-Band Monopole Antenna with Folded Strip Lines for WiMAX/WLAN and ITU Applications

description: Abstract In this article, a small Quad-Band microstrip patch antenna with folded strip lines for WiMAX/WLAN and ITU Applications is presented. This antenna consists eight symmetrical rectangular folded strip lines with 2 PIN diodes, ground plane and dimensions of 15×20×1.6mm3. Using PIN diodes integrated within the antenna configuration, the antenna would be able to operate in two modes. The operational frequency bands of antenna are WLAN (2.4/5.2/5.8GHz), WiMAX (3.5/5.5GHz) and ITU-Region 1 allocation (4.3GHz) when diodes=on. In this design approach of antenna, omnidirectional radiation pattern and S11-10dB bandwidths are obtained for all frequency bands. This antenna is fabricated on FR4 substrate with permittivity of 4.4 and loss tangent of 0.024.
DOI: 10.6084/m9.figshare.5772423.v1
title: A Small Quad-Band Monopole Antenna with Folded Strip Lines for WiMAX/WLAN and ITU Applications

description: Abstract In this article, a small Quad-Band microstrip patch antenna with folded strip lines for WiMAX/WLAN and ITU Applications is presented. This antenna consists eight symmetrical rectangular folded strip lines with 2 PIN diodes, ground plane and dimensions of 15×20×1.6mm3. Using PIN diodes integrated within the antenna configuration, the antenna would be able to operate in two modes. The operational frequency bands of antenna are WLAN (2.4/5.2/5.8GHz), WiMAX (3.5/5.5GHz) and ITU-Region 1 allocation (4.3GHz) when diodes=on. In this design approach of antenna, omnidirectional radiation pattern and S11-10dB bandwidths are obtained for all frequency bands. This antenna is fabricated on FR4 substrate with permittivity of 4.4 and loss tangent of 0.024.
DOI: 10.6084/m9.figshare.5772420
title: Agroforestry system as a buffer zone in a Brazilian Atlantic Forest conservation unit: an artificial nest predation perspective

description: Abstract Here we inferred about the effectiveness of a buffer zone composed by an Agroforestry System (AS) for providing reproductive conditions for Atlantic Forest birds by comparing artificial nest predation rates between a buffer zone, a primary forest area, and a set of small and isolated Atlantic Forest fragments. We have used 237 nests throughout the three areas, of which 100 (42.2%) were depredated. Predation frequencies were 28.6% in the continuous forest, 100% in the AS, and 51.9% in the fragments, differing significantly. We could detect nest predators in 48 of the 100 depredated nests (48%) using camera traps. Differences between areas may be attributed to changes in nest predator species. We support previous evidences that the conservation of bird communities may not rely on buffer zones as an extension of their breeding habitats.
DOI: 10.6084/m9.figshare.5772420.v1
title: Agroforestry system as a buffer zone in a Brazilian Atlantic Forest conservation unit: an artificial nest predation perspective

description: Abstract Here we inferred about the effectiveness of a buffer zone composed by an Agroforestry System (AS) for providing reproductive conditions for Atlantic Forest birds by comparing artificial nest predation rates between a buffer zone, a primary forest area, and a set of small and isolated Atlantic Forest fragments. We have used 237 nests throughout the three areas, of which 100 (42.2%) were depredated. Predation frequencies were 28.6% in the continuous forest, 100% in the AS, and 51.9% in the fragments, differing significantly. We could detect nest predators in 48 of the 100 depredated nests (48%) using camera traps. Differences between areas may be attributed to changes in nest predator species. We support previous evidences that the conservation of bird communities may not rely on buffer zones as an extension of their breeding habitats.
DOI: 10.6084/m9.figshare.5772417
title: Brain changes on magnetic resonance imaging in school-age children who had been preterm infants with intracranial hemorrhage

description: Abstract Objective: To determine whether preterm infants diagnosed with intracranial hemorrhage (by transfontanellar ultrasound) at birth have cerebral lesions that are detectable by magnetic resonance imaging (MRI) upon reaching school age. Materials and Methods: MRI scans of the brain were obtained in 22 school-age children. Fifteen had presented intracranial hemorrhage at birth, and seven had not. We calculated the odds ratio (OR) for the occurrence of brain alterations detectable by MRI and the kappa index for discrepancies among the radiological reports. Results: The children without previous intracranial hemorrhage presented normal MRI findings. Of the 15 children with previous intracranial hemorrhage, 6 (40%) presented brain alterations on MRI: isolated ventricular alteration (dilation and asymmetry), in 2 (13.3%); and ventricular asymmetry accompanied by parenchymal lesion, in 4 (26.7%). The nine remaining children with previous intracranial hemorrhage (60%) presented normal MRI findings. The children with previous intracranial hemorrhage were more likely to present ventricular alteration (OR = 7.8) and parenchymal lesions (OR = 5.4). Conclusion: Ventricular and parenchymal brain alterations detected by MRI suggest isolated morphologic alterations that do not result in neurological impairment detectable on physical examination in school-age children.
DOI: 10.6084/m9.figshare.5772414
title: Evaluation of the use of ashes of scum generated from the Upflow Anaerobic Sludge Blanket reactor as orange inorganic pigment

description: ABSTRACT Scum is a residue generated during the anaerobic treatment of domestic effluents and requires periodical removal in order not to harm the process efficacy. This study aimed to use the scum ashes generated from Upflow Anaerobic Sludge Blanket (UASB) reactor as inorganic pigments. The scum samples collected in different months were thermally treated at 900°C for one hour for removal of organic matter. These ashes were dispersed and submitted to chemical (X-ray Fluorescence - XRF), mineralogical (X-ray Diffraction - XRD), morphological (Field Emission Scanning Electron Microscopy - FE-SEM) and color (Ultraviolet-Visible Diffuse Reflectance Spectroscopy - UV-Vis DRS) analyses. The samples were composed mainly by elements commonly found in the environment. The main crystalline phases are quartz (silicon dioxide - SiO2), anhydrite (calcium sulfate - CaSO4) and hematite (iron oxide - Fe2O3). Also, these particles presented suitable size for application as ceramic pigment and the color obtained was intense orange. When applied as ceramic pigment at the decorative fire temperature, the enameled piece presented intense color and the pigment had good opacity, hiding the ceramic support color, besides, they presented no surface deformations, which indicates the pigments are compatible with enamel. Thus, scum ashes generated in UASB reactor presented interesting characteristics to be applied as ceramic pigments.
DOI: 10.6084/m9.figshare.5772414.v1
title: Evaluation of the use of ashes of scum generated from the Upflow Anaerobic Sludge Blanket reactor as orange inorganic pigment

description: ABSTRACT Scum is a residue generated during the anaerobic treatment of domestic effluents and requires periodical removal in order not to harm the process efficacy. This study aimed to use the scum ashes generated from Upflow Anaerobic Sludge Blanket (UASB) reactor as inorganic pigments. The scum samples collected in different months were thermally treated at 900°C for one hour for removal of organic matter. These ashes were dispersed and submitted to chemical (X-ray Fluorescence - XRF), mineralogical (X-ray Diffraction - XRD), morphological (Field Emission Scanning Electron Microscopy - FE-SEM) and color (Ultraviolet-Visible Diffuse Reflectance Spectroscopy - UV-Vis DRS) analyses. The samples were composed mainly by elements commonly found in the environment. The main crystalline phases are quartz (silicon dioxide - SiO2), anhydrite (calcium sulfate - CaSO4) and hematite (iron oxide - Fe2O3). Also, these particles presented suitable size for application as ceramic pigment and the color obtained was intense orange. When applied as ceramic pigment at the decorative fire temperature, the enameled piece presented intense color and the pigment had good opacity, hiding the ceramic support color, besides, they presented no surface deformations, which indicates the pigments are compatible with enamel. Thus, scum ashes generated in UASB reactor presented interesting characteristics to be applied as ceramic pigments.