cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14305910
title: Effects of Various Sintering Conditions on the Structural and Magnetic Properties of Zinc Ferrite (ZnFe2O4)

description: Abstract Zinc ferrite (ZnFe2O4) nanoparticles have attracted the attention of researchers because of their unique chemical properties and particle-size-dependent magnetic properties. High-surface-area spinel ferrites have numerous technical applications in areas such as high-density information storage, ferrofluids, and catalysis. The coprecipitation technique is the preferred method for preparing nanoscale ZnFe2O4 because it results in a small crystals with a uniform size distribution. In this study, the synthesis was conducted in solution for 48 h, followed by sintering at 1000°C for 1.5–3.5 h. The smallest crystals (70.58 nm) were found in the sample sintered for 2.5 h. Fourier transform infrared spectroscopy (FTIR) functional-group analysis confirmed the presence of Fe–O and Zn–O bonds of cations in octahedral and tetrahedral sites. The ZnFe2O4 sintered for 3.5 h was superparamagnetic. The characterization results suggest that the obtained ZnFe2O4 could be used as a nanofluid in heat exchangers.
DOI: 10.6084/m9.figshare.14305908
title: Evaluation of Stabilizing Additives Content in the Mechanical Properties of Elastomeric Compositions Subject to Environmental and Accelerated Aging

description: This research aimed to evaluate the ideal proportion of two stabilizers in elastomeric compositions indicated for tire sidewall. The stabilizers applied in different proportions were N-1,3-dimethyl-butyl-N'-phenyl-p-phenylenediamine (6PPD) and oligomerized 2,2,4-trimethyl-quinoline (TMQ). Nine compositions were prepared with 0.5, 1.5 and 2.5 phr of 6PPD combined with 0.5, 1.0 and 1.5 phr of TMQ. The compounds were exposed to accelerated aging processes, including thermo-oxidative, photochemical and ozone chamber. Also, the samples were aged in the environment for 440 days. At regular intervals, the samples were evaluated. Gas chromatography was used to quantify the content of 6PPD. Overall, the samples exposed to thermo-oxidative aging showed the greatest loss of mechanical properties (tear and tensile strength) as well as the 6PPD content. From the mechanical strength results, it was possible to conclude that the best combination of stabilizers was 2.5 phr of 6PPD and 1.0 of TMQ.
DOI: 10.5066/p9iybcri
title: Database for the Geologic Map of Three Sisters Volcanic Cluster, Cascade Range, Oregon

description: A database of geologic map of Three Sisters Volcanic Cluster as described in the original abstract: The geologic map represents part of a late Quaternary volcanic field within which scores of eruptions have taken place over the last 50,000 years, some as recently as ~1,500 years ago. No rocks of early Pleistocene (or greater) age crop out within the map area, although volcanic and derivative sedimentary rocks of Miocene and Pliocene age are widespread to the east and west and are certainly buried beneath the younger volcanic field. Of the 145 volcanic map units described herein, only 22 are certainly older than late Pleistocene (&gt;126 ka), and 12 are postglacial (&lt;15 ka). The oldest unit identified yields an age of 532+/-7 ka, and the second oldest, 374+/-6 ka. Compositionally, 10 percent of the units are true basalt; 36 percent, basaltic andesite; 20 percent, andesite; 21.5 percent, dacite; and only 12.5 percent, rhyodacite or rhyolite. Most of the 145 volcanic map units described herein are newly defined, although equivalents of several were described by Taylor, 1978, 1987; Scott, 1987; and Scott and Gardner, 1992. Each is an eruptive unit derived from a single vent or fissure. Some are simple flow units, but many are shields, cones, or stacks of several lava flows that have chemical and mineralogical coherence. Each unit was delineated by field mapping on foot and its integrity confirmed, challenged, or revised by chemical and microscopic work in the laboratory. Definition of a few units required iterative acquisition of field and lab data over a period of years, providing a firm basis for subdividing, lumping, or correlating slightly heterogeneous sequences of lavas. Most units have narrow compositional ranges, but some show zoning or heterogeneity spanning ranges of a few percent SiO2. Orignial map citation: Hildreth, Wes, Fierstein, Judy, and Calvert, Andrew T., 2012, Geologic map of Three Sisters volcanic cluster, Cascade Range, Oregon: U.S. Geological Survey Scientific Investigations Map 3186, pamphlet 107 p., 2 sheets, scale 1:24,000. (Available at https://pubs.usgs.gov/sim/3186/.)
DOI: 10.6084/m9.figshare.14305906
title: Evaluation of the Influence of Particle Size in the Acid Baking Process for the Reduction of Phosphorus Content in Iron Ore

description: Abstract Demand for iron ore worldwide has been steadily increasing, thus implying an increase in the volume of mining resulting in the extraction of ores with higher levels of silicon, phosphorus and sulfur impurities. An extensively used alternative is to perform a pre-treatment of the particles in order to reach the acceptable phosphorus limit in iron ore before its use in steel production. This study aims at the evaluation of the heating process and decrease of the phosphorus content of the particles using microwave energy in iron ore samples percolated by sulfuric acid followed by the leaching technique as a feasible route for the remotion of the phosphorus content in iron ore particles. Using the scanning electron microscopy (SEM) and statistical analysis techniques, it was possible to observe the characteristics of the iron ore particles after treatment with microwave energy. The results indicated that the developed process is feasible. The results of the kinetic simulation contribute to a better understanding of the phenomena of heating using microwave energy and also to the development of new cleaner technologies aiming to improve the efficiency of the acid baking - leaching technique for the reduction of the phosphorus content in iron ore particles.
DOI: 10.6084/m9.figshare.14305905
title: Effect of an Alumina Supported Palladium Catalyst on the Magnesium Sulfate Decomposition Kinetics

description: The sulfur related thermochemical water-splitting cycles are an important class of chemical processes considered for hydrogen production. Recently, the magnesium sulfate thermal decomposition has been reported as a potential unit operation in one of these cycles. Therefore, some interest has been observed in the use of catalysts to lower the activation energy of such reactions. In this context, the present manuscript reports the thermodynamics and kinetics modeling results associated with this reaction system in the presence of a Pd catalyst supported over γ-Al2O3. The presence of such species is responsible for shifting the decomposition temperature to lower values in at least 100 °C. It was observed that the magnesium content is still oriented towards MgO formation. The obtained results indicate that the Pd/Al2O3 catalyst could be a good alternative in reducing the thermal decomposition temperature as its presence was responsible for diminishing the process activation energy from 368.2 to 258.8 kJ.mol−1.
DOI: 10.6084/m9.figshare.14305904
title: Building and Testing a Spin Coater for the Deposition of Thin Films on DSSCs

description: Abstract A low cost spin coater was constructed in this work for the deposition of thin films of titanium dioxide (TiO2) on conductive substrate of FTO (fluoride doped tin oxide) with application on dye sensitized solar cells. The results showed a 95% precision between the speed values obtained by the software of C#sharp language and the spin values observed directly on the device. The TiO2 films deposited through the spin coater with different angular speeds were characterized by UV-Vis optical spectrum, scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrical measurements on an active area of 0.25 cm2. The DSSCs assembled with the TiO2 films of double layer deposited by the spin coater had an efficiency value of 12.74%, while the cell with a single layer presented 4.05% efficiency. Therefore, it is concluded that the spin coater assembled in this study at low costs successfully can produce TiO2 electrodes for DSSCs.
DOI: 10.6084/m9.figshare.14305900
title: Investigation into the Impact Toughness of API 5L X80 Steel Weldments and its Relationship with Safe Welding Procedures

description: API 5L X80 steels are widely used in welded pipes in the petroleum industry. However, microstructural changes in the heat affected zone are a concern when welding such pipes due to the potential formation of regions with low toughness. Despite all the research concerning mechanical properties of welded joints, the acceptance criteria for the qualification of welding procedures are still limited. Welded joints do not always guarantee the safe operation of industrial equipment, because the current Standards adopted are not able to evaluate the properties at some critical regions of the welded joint. This work studied the characteristics of a girth welded joint and showed evidences of low toughness at 0.5 mm from the fusion line due to the micro-phases necklacing the prior austenite grain boundaries. As this feature is not considered by the current Standards for approval of welding procedures, this work proposes an alternative approach to improve the safety of welded structures.
DOI: 10.6084/m9.figshare.14305899
title: Analysis of the Surface Treatments Effect on the Creep Behavior of Ti-6Al-4V Alloy

description: Abstract This paper compares the creep behavior of Ti-6Al-4V alloy after different surface treatments, the plasma nitriding using Plasma Enhanced Chemical Vapor Deposition (PECVD), and the deposition of SiC thin films with Cr interlayer using High Power Impulse Magnetron Sputtering (HiPIMS). A microstructural characterization was performed with Scanning Electron Microscopy (SEM), Scanning and Transmission Electron Microscopy (STEM), and Energy Dispersive Spectroscopy (EDS) techniques. The creep test was performed at a constant load from 500 to 600 °C and 125 to 319 MPa, and a fractographic analysis was performed. The EDS analysis of the plasma nitrided layer indicated the nitrogen presence of the compounds TiN and Ti2N and an increase in the iron concentration. Creep test results in both conditions indicated an increase in the creep resistance. Plasma nitrided condition indicated the lowest creep rate and lesser elongation, making it the most suitable in applications that require a low dimensional distortion.
DOI: 10.6084/m9.figshare.14305898
title: Effect of Cobalt Doping and Milling Time on Microstructure and Vickers Microhardness of the Spark Plasma Sintered (67-x)Ti-xCo-22Si-11B (x = 2 and 6 at-%) Alloys

description: Abstract Ti-6Al-4V and TiAl-based alloys are widely used for fabricating the implantable orthopedic devices and automotive components, respectively. Ti6Si2B-based alloys are attractive for use in orthopedic components because their higher hardness, superior biocompatibility and corrosion resistance in simulated body fluid than Ti and Ti-6Al-4V alloy. Limited information on Ti6Si2B stability in Co-dopped 67Ti-22Si-11B alloys are available in literature. This work presents the effect of cobalt doping and milling time on microstructure and Vickers microhardness of 65Ti-2Co-22Si-11B and 61Ti-6Co-22Si-11B (at-%) alloys produced by spark plasma sintering at 1100 oC for 12min using 20MPa. Samples were characterized by X ray diffraction, scanning electron microscopy, energy dispersive spectrometry, laser particle size analysis, and Vickers microhardness. Sintered alloys with 2 and 6at-%Co indicated the major presence of Ti6Si2B and Ti5Si3 dissolving up to 2.7 and 4.2 at-%Co, respectively, besides the minor precipitates of CoTi2 (4.4-16.7at-%Si) and CoTi (4.6-4.7at-%Si). Vickers microhardness of the sintered 65Ti-2Co-22Si-11B and 61Ti-6Co-22Si-11B alloys were in the range of 950-1050 and 1050-1150HV, respectively. Although the increase from 2 to 6at-%Co has reduced the Ti6Si2B stability, the Co-rich phases increased their hardness values up to 1150HV (11.3GPa), which are superior than those of commercial Ti alloys used for joint orthopedic components and automotive rotating parts.
DOI: 10.6084/m9.figshare.14305893
title: Titanium-dioxide nanostructures grown by dual DC/HiPIMS for dye-sensitized solar cell applications

description: Abstract This work reports how the solar conversion efficiency of dye-sensitized solar cells (DSSCs) depends on the crystalline structure of both the compact TiO2 blocking layer (BL) and homoepitaxially grown porous TiO2 mesoporous structure. The films were grown by simultaneous sputtering of titanium targets by DC magnetron and by high-power impulse magnetron systems (HiPIMS). The deposition conditions were managed to produce in situ dense BLs and porous TiO2 films. The only variable was the polarization of the BLs (0 to -200V). The polarization caused phase transformations from pure anatase phase through rutile-anatase mixed phases to rutile phase. The polarization results in decreasing intensity of the anatase (101) peak of the porous layers. The latter promptly decreased linearly the value of the short-current Isc and exponentially the open-circuit voltage Voc of the cells. Another inference is the surface energy of the BLs, which follows an exponential decay as a function of the film polarization. XPS study of the Ti 2p3/2 – Ti 2p1/2 doublet reveals an appearance of a shake-up satellite, whose area exponentially decreases as the polarization potential rises. This phenomenon is discussed and related with other physical aspects of the homo-epitaxially grown films with different texture. The anatase phase content and its purity predefined by the experimental conditions determine the quality of the DSSC, as well as other components such as the dye type, the electrolyte, and the electrode materials.
DOI: 10.6084/m9.figshare.14305890
title: Titanium-Niobium (Ti-xNb) Alloys with High Nb Amounts for Applications in Biomaterials

description: The present study produced binary titanium-niobium alloys Ti-xNb with high niobium percentage (x = 50, 80 e 90 wt.%) aiming to apply it as a base material in osseous implant devices. The produced TiNb alloys presented a cubic crystalline phase, lower corrosion rate than titanium, lower elastic modulus values, and superior cellular viability than titanium and niobium. The Ti50Nb alloy among all analyzed metallic substrates showed the best values of elastic modulus, corrosion properties, wettability, and cellular viability. Thus, this work suggests a Ti/Nb ratio close to 1 (Ti50Nb) displays optimum characteristics to apply in orthopedic devices.
DOI: 10.6084/m9.figshare.14305886
title: Formation of Gradient Structure in Rails at Long-Term Operation

description: Abstract It has been shown by the methods of physical material science that long-term operation of rails is accompanied by the formation of the gradient structural constituents consisting in the regular change in relative content of lamellar pearlite, fractured pearlite and structure of ferrite-carbide mixture in cross-selection of rail head. As the distance to the surface of rails increases the relative content of metal volume with the structure of lamellar pearlite decreases and that with the structure of fractured pearlite and ferrite-carbide mixture increases. It has been established that the characteristic feature of ferrite-carbide mixture structure is a nanodimentional range of grains, subgrains and particles of the carbide phase forming it. The dimension of grains and subgrains forming the given type of structure varies within the limits of 40-70 nm. The size of carbide phase particles located along the boundaries of grains and subgrains varies within the limits of 8-20 nm.
DOI: 10.6084/m9.figshare.14305884
title: Influence of Si on the Structural, Electrical, and Optical Properties of (Al, Ti, Si)N Films Deposited Via Reactive DC Sputtering

description: Abstract The physical and chemical properties of multifunctional materials have been extensively studied in the last few years especially the mechanical and tribological applications and less attention has taken the electrical and optical properties. Therefore, in this work presents the growth of (Al, Ti, Si)N films deposited on common glass substrates with a maximum thickness of 1024 nm, via reactive DC magnetron sputtering, to analyze the influence of the silicon content on their crystallographic structure, optic and electric behavior. The microstructure of the films was characterized by X-ray diffraction (XRD). The films morphology was evaluated through scanning electronic microscopy (SEM). The optical measurements were carried out by means UV-vis spectroscopy, and the electrical properties were analyzed using a four-point probe. XRD analysis indicated that the films changed from a crystalline phase to an amorphous phase, and the electrical and optical response indicated that the films with higher Si content have l223.6 Ω.cm of resistivity with an energy gap of approximately 1.0 eV and an optical energy gap of 1.5 eV. This electrical property has not been previously reported in these films.
DOI: 10.6084/m9.figshare.14305881
title: Effect of Flux Cored arc Welding Process Parameters on Corrosion Resistance of Austenitic Stainless Steel Claddings

description: Abstract Cladding process can be used to create corrosion resistant surfaces from low cost materials. Austenitic stainless steel has been extensively used for weld cladding. It has excellent corrosion resistance and good weldability. In this context, experiments were conducted by depositing AWS E316LT1-1/4 stainless steel on to AISI 1020 carbon steel and the effects of flux cored arc welding (FCAW) process parameters on pitting and intergranular corrosion was investigated. Response surface methodology (RSM) based central composite design (CDD) was used to predict and develop the mathematical models for process parameters on corrosion resistance. The responses of interest were obtained by double loop electrochemical potentiokinetic reactivation (DLEPR) and potentiodynamic polarization tests. The process parameters analyzed were the wire feed rate, welding voltage, welding speed and nozzle to plate distance. All RSM models developed were statistically significant and presented good adjustments. The results indicated that the process parameters are important in determining the degree of sensitization and pitting potential, and the interaction between parameters cannot be neglected.
DOI: 10.6084/m9.figshare.14305879
title: On the Choice of the Geometrical Extrapolation Models for the Mg-Al-Sr System Based on Experimental Investigation

description: Abstract In the current work, solidification curves were deduced experimentally from Differential Scanning Calorimetric (DSC) using heat transfer model, then compare our experimental work with different extrapolation solidification curves models predicted based on thermodynamic properties of binary sub-systems. The motivation of this work is to better predict ternary thermodynamic properties for binary phase diagram and the error of predicting arises from misjudging the asymmetric component in the asymmetric geometric model, It was found that Kohler gives a better agreement than Muggianu (symmetric model). Tested alloys show that, choosing strontium (Sr) element as the asymmetric component in Mg-Al-Sr system gives the best prediction for solidification curves. In addition, the solidification curves calculated using Toop model for the ternary system (Al or Mg is asymmetric) shows the poorest fit solidification curves construed from DSC data.
DOI: 10.6084/m9.figshare.14305877
title: Preparation and Characterization of CdO/In6Se7 Thin Film Transistors

description: Abstract In this study, the design and characterization of CdO/InSe thin film transistors (TFT) that are grown onto Au substrates are investigated. The devices are also subjected to a vacuum annealing process at 300 oC to enhance the structure and electrical performance. It was observed that the growth of polycrystalline monoclinic In6Se7 phase of InSe is preferred at this annealing temperature when coated onto Au/CdO substrates. Electrically, noisy negative capacitance effect accompanied with resonance-antiresonance phenomena is observed in the capacitance spectra of the as prepared TFT devices. The annealing of the TFT devices reduced the noise in the capacitance, conductance, impedance, and reflection coefficient and return loss spectral responses. The heat treated TFT devices displayed low bandpass, high bandpass and bandstop filter characteristics in the studied frequency domain (0.01-1.80 GHz) indicating the applicability of these devices as radio wave-microwave resonators.
DOI: 10.6084/m9.figshare.14305875
title: Nanostructured Hydroxyapatite from Hen´s Eggshells Using Sucrose as a Template

description: Abstract The nanostructured hydroxyapatite (HAp) was synthesized by precipitation from aqueous phase, using hen’s eggshells and different sucrose concentrations. The XRD results confirmed the formation of HAp, with crystallite size of about 15-22 nm. The SEM and TEM characterization showed morphological changes when increasing the amount of sucrose used, with the tendency to form spheroidal particles. The specific surface area increases from 36 to 93 m2.g-1 as the amount of sucrose used increases. Our results indicated that sucrose can be used as a promising additive/template, easy to obtain at low cost. In addition to contributing to the recycling of this biowaste (eggshells), the synthesized HAp has the potential to be used in bone tissue engineering applications, since the samples were no cytotoxicity to dental pulp stem cells in the in vitro assessment by resazurin assay.
DOI: 10.6084/m9.figshare.14305874
title: Finite Element Analysis of Nylon Based 3D Printed Autonomous Underwater Vehicle Propeller

description: Abstract The recent developments in the additive manufacturing to manufacture complex cost effective profiles is gaining popularity to test the strength of developed products through finite element method (FEM). Finite element analysis (FEA) is a potent tool for mechanical analysis. The combination of 3D printing and FEA is opening new opportunities to go further in the complexity of the product geometry. The autonomous underwater vehicle (AUV) propeller blade has a complex profile with multi-directional gradient and twist, which requires a multi-stage operation to manufacture, including the hubs. The AUV propeller is required to withstand the applied load and generate the required thrust to move AUV at the desired speed. The current study explores the performance of AUV propeller prepared by additive synthesis using Nylon 6 material. The design of the propeller blade was developed using SOLID WORKS and integrated to the CUBPRO (DUO) to obtain the required 3D printing parameters. A comparative investigation is made for Nylon material within the dimensional conformance with the 3D printed propeller blade. The stress-strain analysis of the Nylon AUV propeller is carried with the FEM. The analysis of error and the stress show that the Nylon material meets the performance criteria for AUV propeller.