cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.12094443
title: AEB Online Calculator for Assessing Technology Maturity: IMATEC

description: ABSTRACT: This paper exposes initially the motivations for developing a TRL online calculator by AEB (Brazilian Space Agency; in Portuguese, Agência Espacial Brasileira). Such motivations demand the tool to be a way not only to assess the TRL condition of operational space missions and systems, but also as a method of evaluating and sharing proposals with new technological content. The TRL methodology and its relation to risk management are discussed. The development phases of the IMATEC Lite application are then described, with emphasis to the data handling structure capable of storing the user product model. A result of technology assessment using the software is detailed by presenting the PBS of the SERPENS 1 mission nanosatellite. The prospects of using the tool for judging the acceptability of new missions and projects are discussed, as well as some of the encountered difficulties.
DOI: 10.6084/m9.figshare.12094443.v1
title: AEB Online Calculator for Assessing Technology Maturity: IMATEC

description: ABSTRACT: This paper exposes initially the motivations for developing a TRL online calculator by AEB (Brazilian Space Agency; in Portuguese, Agência Espacial Brasileira). Such motivations demand the tool to be a way not only to assess the TRL condition of operational space missions and systems, but also as a method of evaluating and sharing proposals with new technological content. The TRL methodology and its relation to risk management are discussed. The development phases of the IMATEC Lite application are then described, with emphasis to the data handling structure capable of storing the user product model. A result of technology assessment using the software is detailed by presenting the PBS of the SERPENS 1 mission nanosatellite. The prospects of using the tool for judging the acceptability of new missions and projects are discussed, as well as some of the encountered difficulties.
DOI: 10.6084/m9.figshare.12094500
title: Aerodynamic Performance Estimation of Camber Morphing Airfoils for Small Unmanned Aerial Vehicle

description: ABSTRACT: This paper proposes a methodology to harvest the benefits of camber morphing airfoils for small unmanned aerial vehicle (SUAV) applications. Camber morphing using discrete elements was used to morph the base airfoil, which was split into two, three, and four elements, respectively, to achieve new configurations, into the target one. . In total, thirty morphed airfoil configurations were generated and tested for aerodynamic efficiency at the Reynolds numbers of 2.5 × 105 and 4.8 × 105, corresponding to loiter and cruise Reynolds numbers of a typical SUAV. The target airfoil performance could be closely achieved by combinations of 5 to 8 morphed configurations, the best of which were selected from a pool of thirty morphed airfoil configurations for the typical design specifications of SUAV. Interestingly, some morphed airfoil configurations show a reduction in drag coefficient of 1.21 to 15.17% compared to the target airfoil over a range of flight altitudes for cruise and loiter phases. Inspired by the drag reductions observed, a case study is presented for resizing a SUAV accounting for the mass addition due to the morphing system retaining the benefits of drag reduction.
DOI: 10.6084/m9.figshare.12094500.v1
title: Aerodynamic Performance Estimation of Camber Morphing Airfoils for Small Unmanned Aerial Vehicle

description: ABSTRACT: This paper proposes a methodology to harvest the benefits of camber morphing airfoils for small unmanned aerial vehicle (SUAV) applications. Camber morphing using discrete elements was used to morph the base airfoil, which was split into two, three, and four elements, respectively, to achieve new configurations, into the target one. . In total, thirty morphed airfoil configurations were generated and tested for aerodynamic efficiency at the Reynolds numbers of 2.5 × 105 and 4.8 × 105, corresponding to loiter and cruise Reynolds numbers of a typical SUAV. The target airfoil performance could be closely achieved by combinations of 5 to 8 morphed configurations, the best of which were selected from a pool of thirty morphed airfoil configurations for the typical design specifications of SUAV. Interestingly, some morphed airfoil configurations show a reduction in drag coefficient of 1.21 to 15.17% compared to the target airfoil over a range of flight altitudes for cruise and loiter phases. Inspired by the drag reductions observed, a case study is presented for resizing a SUAV accounting for the mass addition due to the morphing system retaining the benefits of drag reduction.
DOI: 10.5281/zenodo.4641533
title: ASR dataset

description: Voice dataset - Twi
DOI: 10.5281/zenodo.4625647
title: ASR dataset

description: Voice dataset - Twi
DOI: 10.6084/m9.figshare.14271955
title: Effect of the Addition of La2O3 on the Properties of ZrO2-Al2O3 Ceramic Composites for Coatings in Aerospace Turbines

description: ABSTRACT: Ceramic matrix composites have attracted the interest of turbine manufacturers for use in coating hot sections because of their higher capacity to withstand high temperatures and because they have a lower requirement for air cooling. One of the most commonly used ceramic coatings is zirconia-yttria. However, its main disadvantage is the inherent fragility of ceramics, which limits the use of these materials in mechanical structures and industrial applications. Ceramics are generally reinforced with the incorporation of additives to reduce their brittleness and increase their mechanical strength and toughness. It is known that La2O3 which are potential source for stabilization of zirconia composites. In this context, ZrO2-Al2O3-La2O3 based ceramic matrix composites were developed for deposition of a thermal barrier coating on the substrate of exhaust nozzles of aerospace turbines varying the content of La2O3 by 5, 7 and 10 wt%. The composites were produced by a thermomechanical process and sintered at 1385 °C. The properties of these composites were studied by X-ray diffraction, relative density, scanning electron microscopy, and Vickers microhardness tests. The results indicate that the composite with 10% La2O3 has great potential for use as ceramic coatings of turbine exhaust nozzles in the aerospace industry.
DOI: 10.6084/m9.figshare.14271955.v1
title: Effect of the Addition of La2O3 on the Properties of ZrO2-Al2O3 Ceramic Composites for Coatings in Aerospace Turbines

description: ABSTRACT: Ceramic matrix composites have attracted the interest of turbine manufacturers for use in coating hot sections because of their higher capacity to withstand high temperatures and because they have a lower requirement for air cooling. One of the most commonly used ceramic coatings is zirconia-yttria. However, its main disadvantage is the inherent fragility of ceramics, which limits the use of these materials in mechanical structures and industrial applications. Ceramics are generally reinforced with the incorporation of additives to reduce their brittleness and increase their mechanical strength and toughness. It is known that La2O3 which are potential source for stabilization of zirconia composites. In this context, ZrO2-Al2O3-La2O3 based ceramic matrix composites were developed for deposition of a thermal barrier coating on the substrate of exhaust nozzles of aerospace turbines varying the content of La2O3 by 5, 7 and 10 wt%. The composites were produced by a thermomechanical process and sintered at 1385 °C. The properties of these composites were studied by X-ray diffraction, relative density, scanning electron microscopy, and Vickers microhardness tests. The results indicate that the composite with 10% La2O3 has great potential for use as ceramic coatings of turbine exhaust nozzles in the aerospace industry.
DOI: 10.6084/m9.figshare.12094488
title: Transonic Aerodynamic Analysis of Different Forebody Shapes of Aerospace Vehicles

description: ABSTRACT: One of the most important features of an aerospace vehicle design is its shape, especially the forebody part, since it defines the main characteristics of the vehicle aerodynamic. In this context, the present work has the purpose of investigating the transonic aerodynamic regime in typical vehicle models, with different frontal geometry configurations, using the experimental techniques pressure sensitive paint (PSP) and Schlieren. The aim is to get more insights about the flow patterns over the selected models, regarding the transonic regime, in terms of qualitative density field evaluation, and the identification of important aerodynamic parameters, such as shock wave positioning and pressure gradients over the model, as well as the influence of the forebody configuration in the flow pattern. The test campaign was carried out in the Pilot Transonic Wind Tunnel of the Institute of Aeronautics and Space (IAE; in Portuguese, Instituto de Aeronáutica e Espaço), varying Mach numbers from subsonic to low supersonic. Five forebody configurations mounted in a cylindrical body having the standard cone-cylinder shape as baseline was considered. A description of the phenomena occurring around and on the models surface for all five models is presented, through analyses of the Schlieren images and PSP results.
DOI: 10.6084/m9.figshare.12094488.v1
title: Transonic Aerodynamic Analysis of Different Forebody Shapes of Aerospace Vehicles

description: ABSTRACT: One of the most important features of an aerospace vehicle design is its shape, especially the forebody part, since it defines the main characteristics of the vehicle aerodynamic. In this context, the present work has the purpose of investigating the transonic aerodynamic regime in typical vehicle models, with different frontal geometry configurations, using the experimental techniques pressure sensitive paint (PSP) and Schlieren. The aim is to get more insights about the flow patterns over the selected models, regarding the transonic regime, in terms of qualitative density field evaluation, and the identification of important aerodynamic parameters, such as shock wave positioning and pressure gradients over the model, as well as the influence of the forebody configuration in the flow pattern. The test campaign was carried out in the Pilot Transonic Wind Tunnel of the Institute of Aeronautics and Space (IAE; in Portuguese, Instituto de Aeronáutica e Espaço), varying Mach numbers from subsonic to low supersonic. Five forebody configurations mounted in a cylindrical body having the standard cone-cylinder shape as baseline was considered. A description of the phenomena occurring around and on the models surface for all five models is presented, through analyses of the Schlieren images and PSP results.
DOI: 10.6084/m9.figshare.14270258.v1
title: Transatlantic Market Competition Between Hybrid Carrier and Long-Haul Low-Cost Carrier Business Models

description: ABSTRACT: Long-haul low-cost carrier (LHLC) business models are generating considerable interest from the aviation practitioners and academics. Despite the high interest for the LHLC business model, only few have compared the LHLC business model to hybrid carrier business model and studied how airlines can compete with LHLCs. This paper analyses the differences of hybrid and long-haul low-cost carrier models and shows how Aer Lingus airlines has secured its dominant position in the Irish-US market. Product comparison with the help of in-depth interviews with key aviation practitioners as well as secondary data about the capacity and demand of the two carriers in question proves the differences between the two models. Porter five forces model provides an overview of the external competitive environment where the airlines in question operate. The research concluded that the hybrid and long-haul low-cost business model characteristics have many similarities, but also significant differences. It was also discovered that LHLC lack capacity and frequency as well as feeder traffic are very important elements for the transatlantic market. Robust route network including interline traffic and low operating cost, elements present in the hybrid airline business model, ensure profitability.
DOI: 10.6084/m9.figshare.14270258
title: Transatlantic Market Competition Between Hybrid Carrier and Long-Haul Low-Cost Carrier Business Models

description: ABSTRACT: Long-haul low-cost carrier (LHLC) business models are generating considerable interest from the aviation practitioners and academics. Despite the high interest for the LHLC business model, only few have compared the LHLC business model to hybrid carrier business model and studied how airlines can compete with LHLCs. This paper analyses the differences of hybrid and long-haul low-cost carrier models and shows how Aer Lingus airlines has secured its dominant position in the Irish-US market. Product comparison with the help of in-depth interviews with key aviation practitioners as well as secondary data about the capacity and demand of the two carriers in question proves the differences between the two models. Porter five forces model provides an overview of the external competitive environment where the airlines in question operate. The research concluded that the hybrid and long-haul low-cost business model characteristics have many similarities, but also significant differences. It was also discovered that LHLC lack capacity and frequency as well as feeder traffic are very important elements for the transatlantic market. Robust route network including interline traffic and low operating cost, elements present in the hybrid airline business model, ensure profitability.
DOI: 10.6084/m9.figshare.14269855
title: Propellant Combustion Wave Studies by Embedded Thermocouple and Imaging Method at Ambient Pressure

description: ABSTRACT: This paper discusses the method for propellant combustion studies with embedded thermocouple and imaging method at ambient pressure. In this study, three different propellant compositions are experimentally evaluated for surface temperature, flame zone temperature with embedded thermocouple, and reaction zone thickness with high-speed imaging of propellant during combustion at ambient pressure. Preheat zone and flame zone temperature profiles are recorded with time and surface temperature is determined with available models. Observation of these experiments gives the difference between combustion mechanism of double-base propellant with diethylene glycol dinitrate (DEGDN) and 2,4-dinitrotoluene (DNT), composite propellant (CP) and CP with energetic binder. Scanning electron microscope (SEM) images analysis for pristine and quenched sample is also presented.
DOI: 10.6084/m9.figshare.11997243
title: Implementing the LFM-CW MIT Radar at the Ecuadorian Space Institute: Some Results

description: ABSTRACT: This paper deals with the implementation of a version of the MIT LFM-CW radar at the Ecuadorian Space Institute. The effects of near and very near ranges, and free space loss in the performance of the image processing is theoretically revised. Subsequently, the implemented radar is tested in an imaging campaign on a small probing polygon, and very congruent results are obtained.
DOI: 10.6084/m9.figshare.11997243.v1
title: Implementing the LFM-CW MIT Radar at the Ecuadorian Space Institute: Some Results

description: ABSTRACT: This paper deals with the implementation of a version of the MIT LFM-CW radar at the Ecuadorian Space Institute. The effects of near and very near ranges, and free space loss in the performance of the image processing is theoretically revised. Subsequently, the implemented radar is tested in an imaging campaign on a small probing polygon, and very congruent results are obtained.
DOI: 10.6084/m9.figshare.14328945
title: Numerical Simulation of the Boundary Layer Control on the NACA 0015 Airfoil Through Vortex Generators

description: ABSTRACT: This paper studies the influence caused by a vortex generator (VG) on a wing section with NACA 0015 airfoil when this generator is located before and after a recirculation bubble caused by the boundary layer detachment. The study was numerically carried out and concentrated under conditions of flow with Rec = 2.38 × 105 and angles of attack AoA = 3 and 6, characterized by the fact that they undergo detachment of the boundary layer before and after the location of the VG, respectively. The use of the generator in AoA = 3 strongly influenced the reduction of the recirculation bubble, leading to a drag reduction of 1.43%. In AoA = 6 with a bubble recirculation, the effect was much lower, with no well-defined formation of longitudinal vortices, resulting in increased drag and lift at 0.33 and 0.35%, respectively.
DOI: 10.6084/m9.figshare.14328945.v1
title: Numerical Simulation of the Boundary Layer Control on the NACA 0015 Airfoil Through Vortex Generators

description: ABSTRACT: This paper studies the influence caused by a vortex generator (VG) on a wing section with NACA 0015 airfoil when this generator is located before and after a recirculation bubble caused by the boundary layer detachment. The study was numerically carried out and concentrated under conditions of flow with Rec = 2.38 × 105 and angles of attack AoA = 3 and 6, characterized by the fact that they undergo detachment of the boundary layer before and after the location of the VG, respectively. The use of the generator in AoA = 3 strongly influenced the reduction of the recirculation bubble, leading to a drag reduction of 1.43%. In AoA = 6 with a bubble recirculation, the effect was much lower, with no well-defined formation of longitudinal vortices, resulting in increased drag and lift at 0.33 and 0.35%, respectively.
DOI: 10.6084/m9.figshare.14328947
title: Effects of the cervical headgear in growing Angle Class II malocclusion patients: a prospective study

description: ABSTRACT Objective: Evaluate dental and skeletal changes resulting from the exclusive use of the cervical headgear for 15 ± 4 months in the treatment of patients with Class II division 1 malocclusion. Methods: Differences between the beginning (T1) and immediately after the end of the therapy (T2) with the cervical headgear in growing patients (Experimental Group, EG, n = 23) were examined and compared, during compatible periods, with those presented by a group of untreated individuals (Control Group, CG, n =22) with similar malocclusions and chronological age. The cephalometric variables evaluated were: ANB, GoGn.SN, AO-BO, S'-ANS, S'-A, S'-B, S'-Pog and S'-U6 (maxillary first molar). The Shapiro-Wilk and Levene tests were used to evaluate the results. Results: Significant differences were found relative to the ANB, S'-U6, AO-BO, S'-ANS, S'-A, S'-B and S'-Pog variables between T1 and T2 when comparing both groups. No statistically significant variation was found regarding the GoGn.SN angle. Conclusions: The use of cervical headgear promoted distal movement of the maxillary first molars and restricted the anterior displacement of the maxilla, without significantly affecting the GoGn.SN angle.
DOI: 10.6084/m9.figshare.14328947.v1
title: Effects of the cervical headgear in growing Angle Class II malocclusion patients: a prospective study

description: ABSTRACT Objective: Evaluate dental and skeletal changes resulting from the exclusive use of the cervical headgear for 15 ± 4 months in the treatment of patients with Class II division 1 malocclusion. Methods: Differences between the beginning (T1) and immediately after the end of the therapy (T2) with the cervical headgear in growing patients (Experimental Group, EG, n = 23) were examined and compared, during compatible periods, with those presented by a group of untreated individuals (Control Group, CG, n =22) with similar malocclusions and chronological age. The cephalometric variables evaluated were: ANB, GoGn.SN, AO-BO, S'-ANS, S'-A, S'-B, S'-Pog and S'-U6 (maxillary first molar). The Shapiro-Wilk and Levene tests were used to evaluate the results. Results: Significant differences were found relative to the ANB, S'-U6, AO-BO, S'-ANS, S'-A, S'-B and S'-Pog variables between T1 and T2 when comparing both groups. No statistically significant variation was found regarding the GoGn.SN angle. Conclusions: The use of cervical headgear promoted distal movement of the maxillary first molars and restricted the anterior displacement of the maxilla, without significantly affecting the GoGn.SN angle.
DOI: 10.6084/m9.figshare.14328948
title: Complex clinical case with Class III and open bite: stability after seven years

description: ABSTRACT A healthy 15-year-old boy with anterior open bite, edge-to-edge transverse discrepancy, and Class III skeletal relationship sought a nonsurgical orthodontic treatment. The patient was treated with premolars extraction, a Hyrax expander and intrusion mechanics with vertical elastics. This mechanics allowed for excellent facial and occlusal results. The final occlusion presented Class I molar and canine relationships, ideal overjet and overbite, and straight facial profile. Analysis of the posttreatment and follow-up radiographs showed that the treatment outcomes remained stable seven years after active orthodontic treatment. Thus, although combined orthodontic and surgical treatment should be considered for patients with this skeletal malocclusion, this case report proves that well controlled orthodontic movement with the patient’s cooperation can be a valid alternative treatment, with good and stable outcomes for patients who refuse surgery.
DOI: 10.6084/m9.figshare.14328948.v1
title: Complex clinical case with Class III and open bite: stability after seven years

description: ABSTRACT A healthy 15-year-old boy with anterior open bite, edge-to-edge transverse discrepancy, and Class III skeletal relationship sought a nonsurgical orthodontic treatment. The patient was treated with premolars extraction, a Hyrax expander and intrusion mechanics with vertical elastics. This mechanics allowed for excellent facial and occlusal results. The final occlusion presented Class I molar and canine relationships, ideal overjet and overbite, and straight facial profile. Analysis of the posttreatment and follow-up radiographs showed that the treatment outcomes remained stable seven years after active orthodontic treatment. Thus, although combined orthodontic and surgical treatment should be considered for patients with this skeletal malocclusion, this case report proves that well controlled orthodontic movement with the patient’s cooperation can be a valid alternative treatment, with good and stable outcomes for patients who refuse surgery.
DOI: 10.6084/m9.figshare.14328950.v1
title: Different approaches to the treatment of skeletal Class II malocclusion during growth: Bionator versus extraoral appliance

description: ABSTRACT Introduction: Class II malocclusion, which has a significant incidence in the population, may compromise facial esthetics and the smile, as well as the masticatory and respiratory functions. Often associated with skeletal abnormalities, it severely affects and compromises quality of life. An accurate diagnosis is fundamental to prepare a treatment plan to correct dental and skeletal anomalies. Objectives: This study discusses treatment alternatives to the correction of Class II division 1 and 2 malocclusion in growing patients, using a Bionator and an extraoral appliance.
DOI: 10.6084/m9.figshare.14328950
title: Different approaches to the treatment of skeletal Class II malocclusion during growth: Bionator versus extraoral appliance

description: ABSTRACT Introduction: Class II malocclusion, which has a significant incidence in the population, may compromise facial esthetics and the smile, as well as the masticatory and respiratory functions. Often associated with skeletal abnormalities, it severely affects and compromises quality of life. An accurate diagnosis is fundamental to prepare a treatment plan to correct dental and skeletal anomalies. Objectives: This study discusses treatment alternatives to the correction of Class II division 1 and 2 malocclusion in growing patients, using a Bionator and an extraoral appliance.